How much credit to give unknown $5/$10 players?

[luvrhino]

This may be an exercise in futility, but i'm trying to learn how to read unknown $5/$10 and $10/$20 limit players.

Full Tilt Poker
Limit Holdem Ring game
Limit: $5/$10
9 players
Converter

Pre-flop: (9 players) luvrhino is MP3 with A[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/spade.gif[/img]
UTG folds, UTG+1 calls, 2 folds, <font color="#cc0000">luvrhino raises</font>, 2 folds, SB calls, <font color="#cc0000">BB 3-bets</font>, UTG+1 folds, luvrhino calls, SB calls.

Flop: 3[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/diamond.gif[/img] 4[img]/images/graemlins/heart.gif[/img] (7SB, 3 players)
SB checks, <font color="#cc0000">BB bets</font>, <font color="#cc0000">luvrhino raises</font>, SB calls, BB calls.

Turn: 9[img]/images/graemlins/diamond.gif[/img] (6.5BB, 3 players)
SB checks, BB checks, <font color="#cc0000">luvrhino bets</font>, <font color="#cc0000">SB raises</font>, BB calls, luvrhino calls.

River: K[img]/images/graemlins/heart.gif[/img] (12.5BB, 3 players)
<font color="#cc0000">SB bets</font>, BB folds, luvrhino calls.

Results:
Final pot: 14.5BB
<font color="#ffffff">SB showed 3c 3s</font>
<font color="#ffffff">luvrhino mucks Ad Ks</font>

The SB and BB were new to me. After the Flop, i figured that SB most likely had a flush draw and that the BB had AA, AK, or second pair.

Anyway, after the SB's check raise on the Turn, i was fairly certain that he had a set of 3s or 4s. A set of 9s seemed doubtful, as did two pair (unless he cold called twice with K9, which isn't impossible). You'd think he'd re-raise pre-flop if he had both of the remaining kings. Finally, the diamond flush draw should be irrelevant, given that the K[img]/images/graemlins/diamond.gif[/img] was already up there (plus i had the A[img]/images/graemlins/diamond.gif[/img]).

Then the BB cold-called. So, even though i thought i was beat, i called on Turn, ready to call at most one more bet on the River.

There are a couple $5/$10 or $10/$20 players against whom i would lay this down on the Turn...but only a couple. Does that sound too loose? Would you ever fold this on the Turn in a $5/$10 game to this betting?

Finally, any idea what the BB had? He didn't make any complaints about folding AA, but had whined about suckouts at other points. Aside from AA, is there anything else he could have where his line makes sense? Unless he has QQ or JJ and thought we both might have had flush draws?