How many times do I have to tell you, that under AOS, you don't need any other non-immigrant visas (F1,H4,etc). You are in AOS (adjustment of status), so you can wait till you get your GC. If you want to work, you are qualified to apply for an EAD, if you want to saty home, it is okay too. No problem at all.
You can also study full time till you get your degree.
What's the point to switch to H4 if you intend to use EAD in Dec.? It will be invalid once you start using EAD.
Hope you get my point this time. You are fine with pending 485, to study, to work, to do anything.