If the table is loose passive preflop, I don't understand why you're slowplaying AA, you can still be cold called if you 3-bet and, especially as deep, you're missing value against EP opening range.

River, the only hand that beats yours is 55, because I don't think he is betting flop and turn a T-x, even AT. I guess betting small on the river is fine because you don't have many bluffs there (only 76s ?).

OK then I would advise to 3-bet a lot on this table, especially light if you have a great fold equity.

If your opponent puts you always on KK+, he will probably call with hands that have potential to win great pots as deep, including all pocket pairs for setmining and suited connectors. I guess you don't want some players in the blinds to get involved neither since your equity will decrease as the pot comes multiway.

This is just a point of vue, I can understand why you decided at that time to slowplay ;)

So, what happened on the river ?

EZ 3bet, EZ valuebet river. Why would he barrel a set or T to check river. He probably doesnt think you are that strong and will try to value x/raise.

I can't explain that clear,but here it's my plan:
after some hand history,I think the ep player has a leak that he will open 3bb when his hand is like AQs QKs AKo,and open 4bb when he has a big pocketpair(JJ-AA?). he may think the different open size can't be realized. it's true that if I 3bet him here,he will 90% to call,but I am not certain that he will pay off a lot after preflop.
1st, preflop I have the best cards and best position,and no one between us is in.so I can easily handle this hand after preflop. 2nd,flatting does not show a enough strength,he may overplay his hand(90% propobility JJ-KK) in a dry board.

and flop is very good,and he bet pot(overplay style).turn is a good card,but I might raise it. river shits me cause he may think I have Tx to call him twice.but as my read,it's a value bet though it seldom be payed off.