Are you making a fps? Because if so, you propably wont need a complex player model, except if it is multiplayer or has alot of mirrors etc. Maybe it is an idea to make a model of a right or/and left arm(s) with different animations for different weapons. Give this arm (or arms) an action and give the weapon a seperate action.

So you than have:
1. the player model as a dummy model for collision checks with enemy attacks and missiles and for things like player movement.
2. an arm model with various animations and which is passable.
3. a weapon model that 'follows' the player arm, does the damage when it touches an enemy and is passable too.