[Marquis]

I gave these some thought. They are difficult hands and even if you lost them all I don't think there are any giant mistakes.

Hand 1.
It's doubtful that I'd call the river with K-high. A-high and I probably do it. The rest I'm cool with.

Hand 2.
I'd always check behind the river here.

Hand 3.
If he had a hand when you called him on hand 1 I'd be more likely to fold this.

Hand 4.
Calling that river raise is pretty difficult but you should know if he is capable of snapping off a bluff here by now. If he had been bluffing in hands 1 and 3 go ahead and call. The previous action may also warrant a check call on this river even though you caught a piece of it.