Live 1-3 $256 effective
Villain in BB with 87s
Limp early
Late makes it 12
I make it $50 in BB
Limper calls (oopsy)
Raises folds
Pot $63 (50*2+12+SB1 ignore rake)
Flop K97 rainbow
I bet 50, called
Pot $213
Turn 5
I bet all in for their remaining $156
Called (oopsy)
River 9 KQo is good

OK So on the turn my EV of getting it in is:

.2273*369 (213 in pot + their 156 call) - .7727*156 (the amount that I am risking) = -36.7

Is that all correct?

THEN we plug this into a fold equity thingy and

Lets assume they fold 15% of their range

.15*213 = 32 (15% of the time we win 213)
.85*(.2273*369) = 71
.85*(.7727*156) = 102.5

32 + 71 - 102.5 = +0.8

Is that all correct?

Yes, assuming your equity estimates are good.