Wasteland Knight
Adventurer
Short answer to the original question - no. I've seen several barbarian builds in the past few campaigns, and none of them have ever dominated. Good at dishing out some damage, sure. But dominate, nope. As for the question about the -2 AC compared to armor boosting magic items, the same items that boost the barbarian can apply to most any other fighter type character. Most barbarians I've seen go the two-handed weapon route, but the AC penalty for raging plus the lack of a shield usually means at higher levels it not a question if they'll be hit, but how much power attack the monster's going to use