semi-bluffing assumes FE, you likely have none.

Hand 1 - If you have no idea what he has I don't hate a fold on the flop. You only have 6 clean outs (although I doubt this is a flush draw). With QK at least your K or Q might win you the hand.

When you raise, you first have to "call" his bet. So there is .85+.8+.8 = 2.45 in the pot. Your raise is $1.3 so you're giving him almost 3:1 to call (you're essentially betting 1/2 the pot). A 3/4 PSB would be 0.75 * 2.45, or $1.80, for a total bet of $1.80 + 0.80 = $3.60.

In addition to denying him odds, it allows you to build the pot (when you have a good hand), thus balancing your ranges.

Hand 2 - Similarly, he's calling $1.15 into $2.85. This isn't as bad because it's not likely he's drawing to anything and his bet really sucks.

I really don't like the push, what are you trying to accomplish? He's unlikely to fold a T, and you can get a 7 to fold for a lot less.

Aside: As you pay attention there are people who small bet/call with a piece of the board, and ones who small bet/call with draws. If they're very predictable you can bet the turn against draws, and check behind with A high ftw, you can check behind turns vs drawers (usually flush), if the river is a blank bet and they'll fold.