Also a nice review. If you care for a second opinion...
:12: I'm not so sure this is bad. It seems okay to me. I don't know this joseki, and my judgement on these things isn't the best, but in the variation shown, white's shape ends up looking extremely inefficient. A look around at a few references for this position indicates that white usually plays P7 instead of Q6 (since he has a working ladder), so that if this line occurs, P7 ends up in a much better spot.
18: Yes, T2 is better.
26: Terrible. Don't smash your head into the opponent's stones. Black can just connect at M3. White has damaged his own stone at L3. The shape formed by L3 and N4, where black has cut cleanly through, is a "broken shape", and is very bad. To accept a broken shape, you should be getting good compensation. Clearly, N4 isn't any sort of compensation, after N4-M3, white's exchange hasn't done anything useful.
27: Black should just connect at M3. The move in the game by black allows white to break through.
34: Right, white T2 is nice. But move 38 in the variation is a little slow. The only cut this protects is that of the O3 stones, so really, this is just saving the O3 stones, which are not too important.
64: Getting to seal white small and in in sente makes a nice result for black.
71: Note the broken shape here. This is painful for white, although in this sort of shape, it can be acceptable sometimes because black can't cut stop the push at B9.
79: Maybe a little slow. Locally, may be better at F6, to avoid the bad relation between F7 and J5 (it's easy for white to come in through that gap later). The shape at N12 needs attention.
82: Ouch! (for black).
115: Yes, F5 is slow.
144: Before resigning just yet, white still has a move to try: K10.