Currently on L1B; employer being acquired; layoff a strong possibility; considering changing careers.

1. Can I apply to change to an F1 visa without having to leave the US?
2. If yes, how is that done?
3. By when, AFTER layoff, must I apply for F1 without jeopardizing chance of approval?
4. How long does processing take?
5. If layoff happens and I don't have documents needed to apply for F1 yet (e.g., no I-20 yet), can I apply for B instead so I'm not out-of-status, then subsequently apply for F1?
6. If (5) is yes, by when, after layoff, must I apply for B visa?
7. If change to B is approved, how long is it usually good for?
8. If B is denied, does that disqualify me from pursuing change to F?

Thank you.