Questions on two streets AQ

[ISF]

I have been varying my play when I get threebet with AQ sometimes capping and sometimes just calling. Should I routinly cap this. AK would be an auto cap. As well who likes the turn cr vs a turn Check call river bet line.
Party Poker 5/10 Hold'em (6 max, 6 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is UTG with A/images/graemlins/heart.gif, Q/images/graemlins/spade.gif.
<font color="#CC3333">Hero raises</font>, <font color="#CC3333">MP 3-bets</font>, <font color="#666666">4 folds</font>, Hero calls.

Flop: (7.40 SB) 9/images/graemlins/heart.gif, 8/images/graemlins/diamond.gif, T/images/graemlins/diamond.gif <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP bets</font>, Hero calls.

Turn: (4.70 BB) A/images/graemlins/diamond.gif <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP bets</font>, <font color="#CC3333">Hero raises</font>, MP calls.

River: (8.70 BB) 7/images/graemlins/club.gif <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, MP calls.

Final Pot: 10.70 BB

[wuarhg]

Whole hand looks good. I rarely cap AQo unless the opponent is thinking something special about me.