Not sure about this one

[scotty34]

UTG 42/0 after 118 hands and just passive and bad overall.
MP is 32/28 after 50 hands
Button is too loose PF, cold-calls often with easily dominated hands (50/10/1.2). Postflop he randomly gets aggressive from time to time, but goes super passive as soon as his aggression is fired back at.

Party Poker 5/10 Hold'em (6 max, 5 handed) FTR converter on zerodivide.cx

Preflop: Hero is SB with J[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/club.gif[/img].
UTG calls, <font color="#CC3333">MP raises</font>, Button calls, Hero calls, BB calls, UTG calls.

Flop: (10 SB) 5[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
Hero checks, BB checks, <font color="#CC3333">UTG bets</font>, <font color="#CC3333">MP raises</font>, <font color="#CC3333">Button 3-bets</font>, <font color="#CC3333">Hero caps</font>, BB folds, UTG calls, MP calls, Button calls.

Turn: (13 BB) J[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, UTG calls, MP calls, Button calls.

River: (17 BB) 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>

I really don't like how I played this hand. What does anyone do differently?

Don't see how to play it any other way. The intent on the flop should be to C/R MP (whom should autobet the flop) to trap the calling station for more bets. As things played out however, capping the flop is optimal. The only hand you really have to worry about is UTG freezing up and going into calldown mode with the flop set turned underfull (I see passives do this quite often).

[PokerBob]

against a spaz raiser and a dumb cold-caller, I am 3-betting preflop.

[Chairman Wood]

I would prefer to make this 3-bets preflop against this group of players. I don't really know what you're supposed to do the rest of the way differently. You have an incredibly awkward position relative to the pf aggresor. This does seem about the best possible way I think. Especially given your read I would hope to c/r MP with Button in the middle.