Preflop
In a non-ante cash game my default would be to fold this hand from SB. If BB is very tight and passive, I can see going for a steal, but I would never min-raise out of position. You are giving him 3:1 + position on you, so unless he is a complete moron, he is going to call you with any two cards.
Flop
You flopped second pair and a flushdraw, so pretty good flop obviously. You cant really go wrong here, unless you fold. Against very aggressive opponents I lean towards a check-call, but C-betting is certainly going to be +EV as well, and you can easily call a raise. On a coordinated board like this and with deep cash game stacks I would go larger than half pot though. Maybe 2/3 or something like that.
Turn
You improved to a flush, so obviously loving life now. You could get tricky now and go for a check-raise, but the safe option is to just continue betting. That takes away the risk of him checking back, which you really dont want. While you are almost certainly ahead now, there are some bad river cards for you, mainly another diamond, that could either make your hand bad or kill your action. Once again you press the half pot button, and as played on the flop that is probably fine to not give away a bet sizing tell, that you liked the turn card. I would have preferred some larger bets on both streets though.
River
Pretty good card for you once again, since it did not put out a 1-liner to a flush or pair the board. There is also a chance it could have improved him to two pair or a straight, and this time you bet a little larger, which I like.
Conclusion
Overall a well played hand postflop, but preflop needs some work, and I am not a big fan of all this half pot betting. Its something, I have been "guilty" of myself, but in general half pot is not a preferred bet size by solvers. For me it has helped to simply remove this button, because it force me to either bet small or large and to think about, which is most appropriate for the situation. In general dry boards are good for betting small and wet boards like this are good for betting large.