"Chess In the Park": What Continuation Do You Recommend?

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So this is my version of "chess in the park" ala Bobby Fischer at one of my local chess clubs, as there aren't that many parks in Hawaii where you can play. I'm not sure what the rating of my opponent is, I'm guessing like Class C or something. White's opening is not the strongest, as the d-pawn is left hanging with 6. a3? but he has some pretty good tactical and positional play in the middle game that keeps it a game.

One of the club directors was like, "Why did you play 21. Ke7?" I was like, "Opps, I thought with the Queens off the board, it was a semi-endgame position where I wanted my King in the center, and my Rooks would be connected anyway." I ended up wasting tempo castling by hand a few moves later =/

I'm still up a pawn, but they are all under fire. Still, I'm able to cement an advantage by winning an exchange with 29. ... Bg4! However, the is left as is because we didn't have enough time to finish. The Black pawns are sort of vulnerable, but I do spot a weakness White has on the a1-square, so he has to watch out for mate.

So, if played properly who wins this game? How would you rate the position? And what possible continuations do you recommend? Oh and any positional and tactical blunders and inaccuracies you find are always appreciated. Thanks.

this game is won for black from move 6...