But is that underpowered? If they still beat encounters of their level+5, I do not think so. It might still suck, but min-maxing, powergaming and whatever do not necessarily imply "maximum fun to play". The 3E MinMax bogeyman Pun-Pun is probably not really that great as a character for roleplaying purposes or even facing interesting challenges.
And any optimize will probably scoff of picking multiple skill training feats, but that might be exactly what makes a character interesting to play for a player.
No, I think "power" of a character is measured in his ability to beat challenges facing him - and typically in the context of D&D that means combat challenges.