Should I be raising at some point ?

I wouldn't. You raise to get better hands to fold or poorer hands to call and doubt either will occur.

I think flatting the flop is standard. OTT, we can think about a x/r but I don't hate flatting to keep him on the hook, though if we think V isn't going to triple his strong non-nutted hands, we should raise turn or donk river.

What is Vs range? He opened UTG, which usually means a strong hand Axs, pps, broadways - is he raising K9s UTG? That's pretty loose and we should have an idea if V is playing that loose. If V ever open limps, or if V isn't opening a ton, the only combo that beats us is KQ spades.

Would AA/AK/AQ with Qs/A8/KK with Ks/88 triple barrel? Maybe. We've check called twice, V has no reason to believe 2p+ is bad We easily look like we could have Ax and none of the bets are particularly large.

So I'd raise for value on the river. Sucks when we walk into KQss, but I think V has more sets and 2p that will make a crying call. I think we are felting AA more than we are running into KQss. There are 6x more combos of AA and AxKs than there are KQss, and I think AA or AxKs take the same line a lot.

Im not sure if V will bet AQ on river but I think 2p+ yes. im more concerned what called if I check raise river so deep he will have just under £200 back. I dont think AK calls here and maybe just worse flushes

But what flushes does V have? KQss is the only logical flush he has, and I'm not sure that bets flop 100%. I suppose we could give him K9ss or other random ss hand that's just his "favorite". Even if we give him 3 combos, he definitely has AA and maybe has 88. Then you have a smattering of Ksx hands like KsJx that was semi bluffing and rivered a pair and the river is more a weird blocker bet.

We are getting called by AA almost always, if 88 is there that's calling too. AK should call, if he's folding AK we can bluff a lot in the future.

Most other hands probably fold, but sometimes Vs make weird calls if we give them the chance. A hand like A8 is more likely than K9ss and might play this way. It shouldn't call but it wouldn't shock me. The bottom line is that there aren't many combos that beat us and we should give V the chance to make a mistake. AA alone offsets the times we run into a bigger flush and I don't believe anyone is folding top set. Whatever other random stuff he might call with is just gravy.

turn check i get, flop went x-x-b, turn goes x-x-b-c-? so mp still has to act. x/r would narrow his range significantly and possibly push him out with worse. river though i would either lead for 100 or x/r. im never x/c 3 streets with such a strong hand especially when river improves villains range. think KsKx, AxKs