LA +1*.

The +2 gang seems to make several assumptions about the kind of creatures that will be found by this chap. I don't think we should assume that a faster of any significant level with fail a Will save vs a level 1 spell. I think that the abilities innately merit +1. If you could guarantee access to a steady stream of appropriate level casters, that would be different. But you can't. So you can't take into account theoretical abilities your slave has. That's what the * is for, anyways. Swingy stuff.

LA +1*.