Complicated situation. Thanks

I am H-1B visa holder (quoted) based on a full time position. Now due to some reasons, I want to change to part time and look for another part time.

My questions:
1. Do I have to apply new H-1B for the new part time job or just transfer?
2. The second H-1B needs a quota or not?
3. Do you know if it is possible to get approval for a part time only working for 5 hours per WEEK?

Thank you very much for your help.