Will i have any issues with k1 visa

yes, the are concerns. Yes, the immigration process is complicated. Your situation is not entirely clear, but before you could submit a petition...

Can I?

Maybe. This depends on more information that you did not provide. Regardless of whether you can or cannot, it may not be smart. This is a...

I got plea agreement Is gonna affect to my future and to get a green card? Cause I'm not US resident yet

Yes. This has the potential to affect your green card. You need to talk to an immigration lawyer BEFORE you enter a guilty plea.

Can i marry an Us citizen if i have political asylum case

You need to discuss that with a lawyer. This is way too individualized for this forum.

Do I need to go back to USA within 6 months if I have green card and applied citizenship???

Yes, it likely will prevent you from naturalizing. Can't say for sure, but I wouldn't take the risk.

How to calculate Marriage duration for Green card filing?

You start counting from the day you were married. It's not a calculation and there's no mystery formula.

If divorce is filed before naturalization will it affect the process/decision?Case filed March, online completion status Oct2020

You should talk to a lawyer to clarify details because it is not clear enough from your question to provide an accurate answer.

What documents my wife need to show to convince immigration officer that she is coming to visit me and not to permanently stay?

No matter what documents she brings, it is unlikely she will be admitted as a visitor. The more she brings, the better the chance, but if she's...

Over two years is normal for many appeals

Departing USA while pending on I 485?

You may only depart after you have received advanced parole. If you leave without advanced parole, your I-485 will automatically be deemed abandoned.