Peel Flop is ok with your backdoors, the chance to be ahead and with the chance it gets checked down, you have still some hands dominated like KJ and you're ahead against KQ as well and you have hidden outs with the 8 against 66 and 77. So Flopcall is, as you said, mandatory. Turn is tricky against a guy who opens 20% from UTG what i really doubt, considered that he's just got 20 PFR at all so i think we should determine the ORC UTG Range and first look what EQ you have against his entire range and afterwards we deduct some hands he may be checking back with.
Unfortunately your odds were so poor. Just 1:5. You require 8 Outs to call and i don't think you have more than 7 Outs, if at all. Maybe even less, as AT AK 88 AA got you crushed badly. I will extend his range a little bit and add hands like T9s K9s 55 A7s A6s etc. If he really does have 20%, you should definitely call the Turn as well. Against lateranges it's pretty much a snap call , as well as against unknown UTG.
Board: T♦T♠8♣ K♠
Equity Win Tie
MP2 28.49% 22.61% 5.88% { AhJd }
MP3 71.51% 65.62% 5.88% { 55+, A6s+, K9s+, QTs+, JTs, T9s, A9o+, KJo+ }
If he'd bet this range, you should call once more but questionable whether he's gonna bet A6s A9 etc. Lets assume he does check back with the small aces and a few of his AQ combos.
Board: T♦T♠8♣ K♠
Equity Win Tie
MP2 27.67% 22.89% 4.78% { AhJd }
MP3 72.33% 67.55% 4.78% { 55+, AKs, AJs-A9s, K9s+, QTs+, JTs, T9s, ATo+, KJo+, QJo, Ad9c, Ah9c, As9c }
I missed QJo @ the last calculations and if you'll add hands like 98 87s J9s etc, you've got a pretty easy call.
According to the Equilab analysis => Call Turn and it just gets tricky on the River. Against most players, you can fold ui but don't know whether he'S capable of barreling the River with J9s QJ.
If Ax appears on the River, i would donk and get a call from QQ JJ 99 KJ KQ and given the Jx comes, you may consider donk/fold or check/call. Depends on how honest he plays when he raises. I doubt any lowstake reg would raise the River with a worse hand. 
Suggestions?
