villain is playing 47/15/3.4 w/ a BTN Steal of 52%, fold to 3bet of 0%, fold to cbet 47%, and bet IP vs. missed cbet of 60% over 5 hand sample

after running math i really hate check/folding (think my reasoning in-game was that he general isn't too aggressive post-flop and i was unsure of my equity):

the range i assigned villain for stacking off on the flop is (QQ, 99, 66, Q9, Q6, 69, KJT, JT8, T87[5-K], JT[Q,9,6], 87[Q,9,6][5-K], KK87):(52%!AA**)
using the board and filling in the dead cards with my hand, it shows that this range is 30% of his hands that get to the flop (19,707/65359 combos)
we need 45% to b/c the flop and have 29.2% vs. that range, so b/cing is ev neutral (i assigned fold equity as 60%, in event that he peels the flop a bit wider than the range i assigned him for stacking off)

my questions are:
- would u change anything about the range i assigned him for stacking off the flop?
- how would u go about figuring the ev of a x/r?
- what are u usually doing here? does b/f have merits?

thanks