The interview normally will not be before the visa is available.

If you have a work permit you are allowed to work and working will not violate any nonimmigrant status you have. Only unauthorized employment...

Five years after resuming your U.S. continuous residence, so 2025.

Perhaps CIS will approve the adjustment. Perhaps they will deny it. It depends on the facts.

It could very well be a problem. You should try immediately to get it fixed.

You can leave and return to the U.S. with your unexpired passport and unexpired green card.

You should stop working for your current employer immediately upon approval of the new H1b.

There are generous provisions for a nonimmigrant waiver, depending on the crime. Regarding an immigrant visa waiver, again it depends on the crime.

It will show up show up on his security clearance.

Odds of bond are high. Odds of approval depend on the facts and whether he can show he is in danger of persecution based on his race, religion,...