What are the documents required for persuing a MS program degree in US on L2 visa with a valid EAD?

Talk to the DSO at the college you want to attend and see what they have to say,.

Need my wife and kids to be in USA for upto 6 months before we move out of USA.

They cannot stay behind in the USA once you are no longer on L1 employment.

How long does the immigration court and "removal" process take?

I agree. You can ask for VD and this way bring the removal proceedings to a closure rather soon. If the goal is to leave the USA, this is the...

Joined new employer using my EAD but did not inform my past H1B employer?

Is the job offer underlying the I -140 still valid? Is the new job in the same or similar occupation?

I have detention only certification and I bailed out within 12hours. Do I need to worry about getting citizenship?

It might not be fatal to your naturalization application but will definitely create issues.

H4 and other benefits are issued by the US Government and only the Government can cancel or revoke them.

Visa stamp

In State you cannot get a visa stamp. You need a consulate interview for the visa to be stamped.

Will I get inmigration status if I marry my CU6 Cuban boyfriend?

Non Cuban spouses of Cuban adjustment beneficiaries are allowed to also adjust if the requirements are met.

My wife is in the process for permanent residency, we are awaiting a date for our interview and we may need to cancel

How long did she overstay for? Are you saying you are no longer interested in staying in the USA?

Change of status from F2 to F1?

I agree. The way I understand it, the last status approved would be the status you will be on.