Time Link to 00:47:00
Again with the river check raise, I don't see how we can rep that much of a hand. I understand his range is weak but ours looks even weaker. When you say Tx makes a lot of sense for him (on the turn after he checked), would you expect him to bet the river? We really don't, and I think he knows this because betting flop and checking back turn is a stereotypical sign of weakness in NLHE. Given that, he will just expect us to lead river with our value hands (because it looks like he gave up / is checking back river) and check our marginal hands hoping he checks behind. We should very rarely have a hand we're check raising for value here unless I'm really missing something.
On the turn I don't really agree that he is still barreling AQ or AK. What's our perceived flatting range in the SB with the fish in BB? Small pairs for set value (22-99), things like JTs and maybe 89s, KQ for sure, maybe QJ/KJ. Lots of hands that we would/could 3bet but aren't because of the fish in the BB (assuming this guy is a fish). Of that range on the flop, 22,33,44,66 are either check/folding or occasionally check/raising (to take it down)... very rarely check/calling. So then of our range on the turn, the only marginal hands left (i.e. the ones he could theoretically expect us to fold to a turn barrel) are 88 and 99, and as you said even those probably aren't folding right there. The rest of our range is top pair (QJ,KJ, maybe AJ) straights (89s), 2 pair (JT), sets (77 & 55 mostly), and KQ.... so he could be expecting us to check/raise the turn a ton of the time or at least be check/calling with our top pairs, making a turn barrel really not that profitable. So it's possible in my opinion that he's giving up with AQ/AK some of the time ...... he also might have checked back KQ, thinking that he doesnt want to get check raised off a hand that has so many outs.
I guess what I'm thinking on the river after he bets is that his range is KQ, AQ, AK, Kxdd, Axdd. With AQ he 3bet jams, Axdd he snap folds... the rest he could potentially look us up with given our line doesnt really look that credible (at least to me it wouldnt). Even with all of this analysis this still might be a good spot to check raise for the simple fact that generally speaking, people don't check raise bluff on the river. Given that he tanked he probably thought something was going on here so I would be hesitant to just assume that we're very credible here, especially once people catch you doing this.