Couple of questions about 485, please help me out, thanks

1. My hu*****and has an approved H1-B visa but it will be effective after 1, October. If I applied for the EAD for him, does the EAD application affect his current H1-B status?

2. Since I may move during my application for I-485, I wonder if I can rent a mailbox in the post office as my home address during this period. Or can I use my office address for this purpose?

Thank you sooooooooooooooo much for all of your help.