New SH-player seeking multiple advise

[StellarWind]

Hand 3 depends. 1/2 is full of passive players who rarely checkraise the flop without something good. Naturally that's an easy fold.

But theoretically speaking folding KT and all worse hands you might have is folding way too many hands and is easily exploitable. Especially with a decent backdoor you need to see the turn against a tough or merely laggy opponent.