Against a 5bet you either need to call, or fold depending on the size obviously. Putting in 150+ won't be too great.
I think you can cold4b JJ-TT, AQ as well. Being deeper we'll face less 5bets in general, so we'll be able to realize more equity, which makes them a good 4bet IMO.

OTF I think it is close. Betting, checking both has their merits. Since he can have TT,88 but you can't, he can put really big pressure on you with raises here. Being deep with a non-nut hand we should think about pot-controlling more than in other cases.
The pros of betting is that you likely get 1 street from 99,JJ and you need protection against AK.

I think I would check this combo with the diamond, and bet without it, although we might get raised less often holding a diamond. It's definitely a pretty close and very player dependant spot. Against passiveish guys I'm more inclined to bet, against aggros I might check here 100%.

Preflop vs a 5bet: it depends on who 5bets and to what sizing to make a decision between call or fold. Getting it in this deep without a read is not really good.

Postflop: I would check his postflop stats and if he's aggro I would xb and if he's more passive I would bet.

I wouldnt expect most villains to get out of line too much, so I slightly prefer betting.
Checking and calling down is certainly also fine though

preflop I'd prob just fold vs reasonably sized 5b