Black in the Kings indian

I am stuck on 1500 (rapid) for more than 1 month. I play scotch and queen's gambit with white and sicilian or queen's gambit decline/accept with balck... Whic openings should i try to get an good middle game position

There's nothing wrong with the Queen's Gambit as Black (or White).

Why do you think your problems are connected with the opening? More likely, you need to learn more about middle-game planning.

GM Larry Evans' method of static analysis - Chess Forums - Chess.com

when white plays a deviating sideline that you dont understand, its often best to play c5 and transpose into a benoni structure

It's crazy that you guys get play in the Benoni. Whenever I employ it against my opponents , I just get suffocated with no counterplay and I just choke out. Thinking of trying out the benko though. Let's see how that goes.

could you show your games in the benoni as black?

its normal for black to be cramped in the Benoni. black needs to trade off some minor pieces before being able to get active.

you just dont know your opening well enough, your opening was inaccurately played and you focused where focus was not needed and you gave white a strong initiative which eventually made you crumble.

white also played extremely well

It's not worth it. White doesn't allow any counterplay. See my other games.

Have you tried playing it as a King's Indian and only playing c7-c5 after White strays out of "best Benoni" lines?

See my game in Post #5 where I got LOTS of counterplay by entering a delayed Benoni.

that is what typically works best if you are a benoni player

I agree. But the Benoni structure is not de rigueur in the KID, especially in a sideline like 4.Bg5.

the Averbahk with Bg5 is a different animal.

personally, I like an early c5 by Black and Nbd7.

There are several ways to force c7-c5 through.

Na6 makes more sense than it looks, since after Black's c7-c5 and White's d4-d5 reply, Black can follow up with Nc7, Rb8 and a6 forcing b7-b5 through.

Na6 is good.