200nl combo draw 4-way pot vs. two donkeys

[holdem2000]

BU is 90/60 over 40 hands (his raises are usually between $4 and $8, and he'll usually bet all streets so I'm fine with my preflop play), CO is 64/14 over 36 hands, UTG+2 is 33/14/.98 over ~400.

I raised the flop for value since I have huge equity and hope for at least two callers... think it should have been smaller? Or do you not like the flop raise because it opens up the action again and I may wind up heads up? Then should I check through the turn?

Poker Stars, $1/$2 NL Hold'em Cash Game, 9 Players
LegoPoker Hand History Converter

UTG+1: $228.40
UTG+2: $496.05
Hero (MP1): $282.20
MP2: $216
CO: $112
BTN: $744.60
SB: $521
BB: $164.15
UTG: $82

Pre-Flop: 6[img]/images/graemlins/diamond.gif[/img] 4[img]/images/graemlins/diamond.gif[/img] dealt to Hero (MP1)
UTG folds, UTG+1 calls $2, UTG+2 calls $2, Hero calls $2, MP2 folds, <font color="red">CO raises to $10</font>, BTN calls $10, SB folds, BB calls $8, UTG+1 calls $8, UTG+2 calls $8, Hero calls $8

Flop: ($61) 9[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/diamond.gif[/img] 7[img]/images/graemlins/heart.gif[/img] (6 Players)
BB checks, UTG+1 checks, UTG+2 checks, Hero checks, <font color="red">CO bets $20</font>, BTN calls $20, 2 folds, UTG+2 calls $20, <font color="red">Hero raises to $70</font>, CO calls $50, BTN folds, UTG+2 calls $50

Turn: ($291) A[img]/images/graemlins/spade.gif[/img] (3 Players)
UTG+2 checks, Hero ??