H1 to H4 - Clarification

[maverickman]

Here is a scenario I needed some specific clarifications. If you could please address my questions below individually it will help.

My wife is currently working on an H1B with a reputed firm. She is planning to quit at this time which would mean they will be revoking her H1 at this time. She will need to move into H4 status to have a valid status.

The clarifications that I would need on this is

1) How long does it take for the H1 to H4 process be completed.

2) If she gets a job during this period of transfer and the employer agrees for her H1 B can she file a new petition?

3) If she can file a new petition, can she start working prior to October?

4) Will there be cap limit for the application?

Although there were lot of similar questions I was not able to identify all the answers to my questions. Help in this regard will be appreciated.