Hi Lunitis,
Preflop: may seem a bit loose since SB is a shortie however he seems to be folding to cbets and is overall passive so it's fine.
Flop: This is a flop texture that's very wet and villain can hit it many ways. Since he doesn't donk much and is overall passive I would assume that his range hit this board nicely (pair, pair+draw, draw, etc) so I would look at making the raise larger for pure value.
In fact I'd look at making the raise big enough so I can ship the turn without overbetting.
For example a $3.5 raise would make the pot $8.55 on the turn with ~$7 behind.
As played the pot is $6.15 with ~$8 behind. So always plan your hand out early on.
As played I'd still bet but probably something like $2 to induce him to make a mistake. I can't see us getting away from this if he has a flush but his range is wider than that.