diff --git a/slurm_qos/tasks/main.yml b/slurm_qos/tasks/main.yml
index a909786..4ea8a28 100644
--- a/slurm_qos/tasks/main.yml
+++ b/slurm_qos/tasks/main.yml
@@ -1,25 +1,50 @@
 ---
-- name: Ensure Slurm QoS exist
+- name: Validate QoS settings
+  ansible.builtin.assert:
+    that:
+      - item.name is defined
+    fail_msg: "QoS entry missing 'name': {{ item }}"
+  loop: "{{ slurm_qos_settings }}"
+  when: slurm_qos_assert_vars | bool
+
+- name: Validate account settings
+  ansible.builtin.assert:
+    that:
+      - item.name is defined
+    fail_msg: "Account entry missing 'name': {{ item }}"
+  loop: "{{ slurm_qos_accounts }}"
+  when: slurm_qos_assert_vars | bool
+
+- name: Validate user settings
+  ansible.builtin.assert:
+    that:
+      - item.username is defined
+    fail_msg: "User entry missing 'username': {{ item }}"
+  loop: "{{ slurm_qos_users }}"
+  when: slurm_qos_assert_vars | bool
+
+- name: Ensure Slurm QoS configured
   when: slurm_qos_settings | default([]) | length > 0
   block:
-    - name: Check Slurm QoS list
+    - name: Check existing Slurm QoS
       ansible.builtin.command: "sacctmgr -Pn show qos format=name"
       register: qos_list
       changed_when: false
       failed_when: false
 
-    - name: Add Slurm QoS (if missing)
+    - name: Add missing Slurm QoS
       ansible.builtin.command: "sacctmgr -i add qos {{ item.name }}"
       loop: "{{ slurm_qos_settings }}"
       loop_control:
         label: "{{ item.name }}"
       when: qos_list.stdout is not search(item.name)
-      changed_when: true
+      register: qos_add
+      changed_when: qos_add.rc == 0
 
-    - name: Modify Slurm QoS (if already exists)
+    - name: Configure Slurm QoS
       ansible.builtin.command: >
         sacctmgr -i modify qos where name={{ item.name }} set
-        {% if item.max_tres is defined and item.max_tres is not none %}MaxTRES={{ item.max_tres }}{% endif %}
+        {% if item.max_tres_per_user is defined and item.max_tres_per_user is not none %}MaxTRESPU={{ item.max_tres_per_user }}{% endif %}
         {% if item.max_submit_jobs is defined and item.max_submit_jobs is not none %}MaxSubmitJobs={{ item.max_submit_jobs }}{% endif %}
         {% if item.max_jobs_per_user is defined and item.max_jobs_per_user is not none %}MaxJobsPerUser={{ item.max_jobs_per_user }}{% endif %}
         {% if item.grace_time is defined and item.grace_time is not none %}GraceTime={{ item.grace_time }}{% endif %}
@@ -27,8 +52,9 @@
       loop: "{{ slurm_qos_settings }}"
       loop_control:
         label: "{{ item.name }}"
-      when: qos_list.stdout is search(item.name)
-      changed_when: true
+      register: qos_modify
+      changed_when: qos_modify.rc == 0
+      failed_when: qos_modify.rc != 0 and "Nothing modified" not in qos_modify.stdout
 
 - name: Ensure Slurm accounts exist
   when: slurm_qos_accounts | default([]) | length > 0
@@ -44,6 +70,11 @@
         slurm_cluster_name: "{{ cluster_list.stdout_lines[0] }}"
       when: cluster_list.stdout_lines | length == 1
 
+    - name: Fail if multiple clusters detected without explicit config
+      ansible.builtin.fail:
+        msg: "Multiple clusters found. Set 'slurm_cluster_name' explicitly."
+      when: cluster_list.stdout_lines | length > 1 and slurm_cluster_name is not defined
+
     - name: Check if Slurm account exists
       ansible.builtin.command: "sacctmgr -Pn list account name={{ item.name }} format=account"
       register: account_check
@@ -66,7 +97,7 @@
       when: item.stdout is not search(item.item.name)
       changed_when: true
 
-- name: Ensure Slurm users exist with partition limits
+- name: Ensure Slurm users and partitions configured
   when: slurm_qos_users | default([]) | length > 0
   block:
     - name: Check existing Slurm users
@@ -75,96 +106,103 @@
       changed_when: false
       failed_when: false
 
-    - name: Add Slurm user if not already present
+    - name: Add new Slurm users if missing with default preempt partition
       ansible.builtin.command: >
         sacctmgr -i add user name={{ item.username }}
         cluster={{ slurm_cluster_name }}
         account={{ item.sponsor | default('orcd') }}
-        {% if item.partitions is defined and item.partitions | length > 0 %}
-          partition={{ item.partitions | map(attribute='name') | join(',') }}
-        {% else %}
-          partition=debug,preempt
-        {% endif %}
-        {% if item.qos_list is defined and item.qos_list | length > 0 %}
-          QOS={{ item.qos_list | join(',') }}
-        {% else %}
-          QOS=debug_qos,preempt_qos
-        {% endif %}
-        {% if item.qos_default is defined %}
-          DefaultQOS={{ item.qos_default }}
-        {% else %}
-          DefaultQOS=preempt_qos
-        {% endif %}
-        {% if itm.comment is defined %}Comment="{{ item.comment }}"{% endif %}
+        partition=preempt
+        QOS=preempt_qos
+        DefaultQOS={{ item.qos_default | default('preempt_qos') }}
+        {% if item.comment is defined %}Comment="{{ item.comment }}"{% endif %}
       loop: "{{ slurm_qos_users }}"
       loop_control:
         label: "{{ item.username }}"
       when: user_list.stdout is not search(item.username)
-      changed_when: true
+      register: user_add
+      changed_when: user_add.rc == 0
 
-    - name: Check existing partition associations
-      ansible.builtin.command: |
-        sacctmgr -Pn show assoc where user={{ item.username }} cluster={{ slurm_cluster_name }} account={{ item.sponsor | default('orcd') }} format=Partition,GrpTRES,MaxNodes
-      register: assoc_check
+    - name: Configure Slurm user attributes
+      ansible.builtin.command: >
+        sacctmgr -i modify user where name={{ item.username }}
+        cluster={{ slurm_cluster_name }}
+        account={{ item.sponsor | default('orcd') }} set
+        {% if item.comment is defined %}Comment="{{ item.comment }}"{% endif %}
       loop: "{{ slurm_qos_users }}"
       loop_control:
         label: "{{ item.username }}"
-      when: user_list.stdout is search(item.username)
+      register: user_modify
+      changed_when: user_modify.rc == 0
+      failed_when: user_modify.rc != 0 and "Nothing modified" not in user_modify.stdout
+
+    - name: Check existing partition associations for users
+      ansible.builtin.command: >
+        sacctmgr -Pn show assoc where user={{ item.username }}
+        cluster={{ slurm_cluster_name }}
+        account={{ item.sponsor | default('orcd') }}
+        format=partition
+      loop: "{{ slurm_qos_users }}"
+      loop_control:
+        label: "{{ item.username }}"
+      register: assoc_check
       changed_when: false
       failed_when: false
 
-    - name: Ensure partition associations exist for existing users
+    - name: Add missing partition associations for users
       ansible.builtin.command: >
         sacctmgr -i add user name={{ item.0.username }}
         cluster={{ slurm_cluster_name }}
         account={{ item.0.sponsor | default('orcd') }}
         partition={{ item.1.name }}
-        {% if item.1.name == 'admin' %}
-          QOS=admin_qos DefaultQOS=admin_qos
+        {% if item.1.qos is defined %}
+          QOS={{ item.1.qos }}
+          DefaultQOS={{ item.1.qos }}
         {% else %}
-          QOS={{ item.0.qos_list | join(',') }} DefaultQOS={{ item.0.qos_default | default('preempt_qos') }}
+          QOS={{ slurm_partition_qos_defaults[item.1.name] | default(item.0.qos_default | default('preempt_qos')) }}
+          DefaultQOS={{ slurm_partition_qos_defaults[item.1.name] | default(item.0.qos_default | default('preempt_qos')) }}
         {% endif %}
-      loop: "{{ slurm_qos_users | subelements('partitions') }}"
+      loop: "{{ slurm_qos_users | subelements('partitions', skip_missing=True) }}"
       loop_control:
         label: "{{ item.0.username }} - {{ item.1.name }}"
-      when:
-        - user_list.stdout is search(item.0.username)
-        - assoc_check.results | selectattr('item.username', 'equalto', item.0.username) | map(attribute='stdout_lines') | flatten | join(',') is not search(item.1.name)
-      changed_when: true
+      when: >
+        assoc_check.results | selectattr('item.username', 'equalto', item.0.username) | map(attribute='stdout') | join('') is not search(item.1.name)
+      register: assoc_add
+      changed_when: assoc_add.rc == 0
 
-    - name: Debug partition-specific limits
-      ansible.builtin.debug:
-        msg: >
-          For {{ item.0.username }} - {{ item.1.name }}:
-          grptres={{ grptres | default('unset') }},
-          max_nodes={{ max_nodes | default('unset') }}
-      vars:
-        partition_defaults: "{{ slurm_qos_partition_defaults.partitions[item.1.name] }}"
-        grptres: "{{ item.1.grptres | default(partition_defaults.grptres) }}"
-        max_nodes: "{{ item.1.max_nodes | default(partition_defaults.max_nodes) }}"
-      loop: "{{ slurm_qos_users | subelements('partitions') }}"
-      loop_control:
-        label: "{{ item.0.username }} - {{ item.1.name }}"
-      when: user_list.stdout is search(item.0.username)
-
-    - name: Update partition-specific limits (GrpTres only)
+    - name: Ensure partition associations for users (defined partitions)
       ansible.builtin.command: >
         sacctmgr -i modify user where
         name={{ item.0.username }}
         cluster={{ slurm_cluster_name }}
-        account={{ item.0.sponsor | default('orcd') }}
-        partition={{ item.1.name }}
-        set
-        {% if grptres is defined and grptres is not none %} GrpTRES={{ grptres }}{% endif %}
-      vars:
-        partition_defaults: "{{ slurm_qos_partition_defaults.partitions[item.1.name] }}"
-        grptres: "{{ item.1.grptres | default(partition_defaults.grptres) }}"
-        max_nodes: "{{ item.1.max_nodes | default(partition_defaults.max_nodes) }}"
-      loop: "{{ slurm_qos_users | subelements('partitions') }}"
+        account={{ item.sponsor | default('orcd') }}
+        partition={{ item.1.name }} set
+        {% if item.1.qos is defined %}
+          QOS={{ item.1.qos }}
+          DefaultQOS={{ item.1.qos }}
+        {% else %}
+          QOS={{ slurm_partition_qos_defaults[item.1.name] | default(item.0.qos_default | default('preempt_qos')) }}
+          DefaultQOS={{ slurm_partition_qos_defaults[item.1.name] | default(item.0.qos_default | default('preempt_qos')) }}
+        {% endif %}
+      loop: "{{ slurm_qos_users | subelements('partitions', skip_missing=True) }}"
       loop_control:
         label: "{{ item.0.username }} - {{ item.1.name }}"
-      when:
-        - user_list.stdout is search(item.0.username)
-        - grptres is defined and grptres is not none
-      changed_when: true
-      failed_when: false
+      register: assoc_modify
+      changed_when: assoc_modify.rc == 0
+      failed_when: assoc_modify.rc != 0 and "Nothing modified" not in assoc_modify.stdout
+
+    - name: Ensure default preempt partition association
+      ansible.builtin.command: >
+        sacctmgr -i modify user where
+        name={{ item.username }}
+        cluster={{ slurm_cluster_name }}
+        account={{ item.sponsor | default('orcd') }}
+        partition=preempt set
+        QOS=preempt_qos
+        DefaultQOS={{ item.qos_default | default('preempt_qos') }}
+      loop: "{{ slurm_qos_users }}"
+      loop_control:
+        label: "{{ item.username }}"
+      when: item.partitions is not defined or item.partitions | length == 0
+      register: default_assoc_modify
+      changed_when: default_assoc_modify.rc == 0
+      failed_when: default_assoc_modify.rc != 0 and "Nothing modified" not in default_assoc_modify.stdout