This reminds me of a sort of King's Indian in reverse after d5. I think the bishop is uncomfortable here, because most of the time it's going to get traded off on f6 without any real gain. So might as well play Nc3 and stall the bishop's placement. Then, if black plays d4 locking it up, Nce2 and play for f4 kingside expansion sort of thing, followed by Nf3 eventually and 0-0. With that kind of a setup, the bishop isn't half bad sitting at home on c1.

When White plays starts out with g3 and bg2 it is known as the Ben Larson attack. It was very popular in the 1970s but fell out of disfavor because black equalizes very quickly. As for 5. bg5 it is not in the spirit of the openning as the Ben Larson aims to establish light square dominance in the center. Better for White is 5. exd5 Nxd5 6. Nf3 Bd6 7. 0-0

More like a Reverse Pirc than a reverse KID. Usually known as the Benko Attack because of Benko's success with it in the 1962 Curacao Candidates where he used it to defeat Bobby Fischer. Reti once tried 1g3 against Alekhine with the idea of playing a reverse Alekhine's defense. Reti's experiment didn't turn out too well.

Great move! now white will pay for his poor choice of moves.

You are right in seeing that the queenside has potiental but the problem is that there is no real way to force an advantage on that side. After 8. ...Bb4+ white can simply send black home packing with 9. c3 Bc5 10.Nbd2! dxc3 11. bxc3 and white has the better of it on the queenside. However, the big key to this position is that the center is sealed. This means that a flank attack will most likely succeed. If you look on the kingside all of white's pieces are pointing in the wrong direction to defend. So the whole situation on the kingside lends itself to a pretty nice kingside pawn swarm with.. 8. ...h5! and here is a quick analysis of the top three ways for white to defend. 9. Nbd2!(this is the only real way to stop the kingside attack) g4 10. h4 g5 Ng1 and the kingside attack is stopped at huge price of space basly placed pieces. 9. h4 Bg4 10. a3(anything else leads to neavy losses) g6(freeing the DSB) 11. Nbd2 Bh6 9. c3 g5 10. h4 g5 11. Nfd2 Bh6 12. Nb3 Qd6 13. c4 0-0 long story short

This might have worked if white didn't have counter-tactics like Qa4+, since there are tactical ideas with Bg4 that almost get there, but I don't think space alone is worth it when white can castle safely and just be calm and use the open b and c files, for instance.

I think 11.Nbd2 was better.

I am glad you saw the mistake and know how to fix it. In the future deal with the safety of your king before you attack or open the center

But since the pawns need pieces to assist them and you're already a piece down, I think it's not so good to exchange pieces. The relative value of white's material edge grows larger with every exchange.

here the queen exchange makes sense for you since you have an advanced past pawn on a4.

Now black is winning.