Don't allow "Delete this field" if a module is activated Inside "Article" type, I have a field called 'field_xenforo_thread_id' (machine name), It's possible to disable the "Delete" option only for this field and only if my module is activated please ?

If the module is activated and if the administrator remove this field, the module is broken and I want prevent this problem.
The module field lock allows you to lock fields for certain roles. You can use that module out of the box or you can copy it and adjust it so that the fields only lock if your module is activated.