so, let me get this organized.

My level 1 feats would be Adamantine Body, Toughness, and Trollbooded (as weird as that sounds), with taking two flaws (possibly Murky-Eyed and Shaky) to get regeneration on a thing that isn't even supposed to have natural healing, then taking dungeon crasher and warforged Juggernaut one my following levels to make a critter that's immune to everything but fire and acid, which I can get energy resistance items for?

Wow. That's pretty awesome