Yes that is sufficient to indicate.

Yes this will impact his GC case as his marital status will change.

How far out is an immigration interview usually scheduled once NVC provides an appointment date? a few weeks? couple of months?

There is no set time for scheduling of interviews due to considerable Covid delays.

Will my 3 children benefit along with our humanitarian revalidation request? Or will i benefit only?

Best to discuss your case directly with retained counsel.

Nvc case review?

It can take 30-90 days for review after resubmission.

It is good to have the previous filing available as reference although not required.

Yes you must submit the police clearance with NVC for your case to be transferred for interview.

You must provide the police clearance to NVC.

Other options may be available to her if not through you but that is for her to determine, not for you to investigate.

I have k1 I 129f visa waiting for approval I asked for a expite request twice both time was denied

No this shouldn’t result in longer wait times if your request for expedited processing is denied.