In the the last installment of Cardplayer, Rolf Slotbloom has an excellent article on why it is good to limp with hands like AQ and AJ on the button rather than raise. His rationale (without going into it too much, since you can go read the article yourself by clicking here;
http://www.cardplayer.com/poker_maga...es/?a_id=14121 ) is that by raising, you make it difficult for yourself to defend a hand which isn't going to be favorable for you most of the time. Read the article, it'll help.
I also agree that you might consider devaluing AQ from your list of premium hands. It'll get you into a lot of trouble if you consider it as such.