Xiaobaitu - help on F1/h1b/i485 pending

Thanks a bunch xiaobaitu for your previous advice - much appreciate it! Want to further clarify and design a good strategy for safe net.

My wife: i485 pending + h1b
Me: i485 pending + phd student (f1 deactivated due to traveling abroad) + EAD/AP

Q1: if i got a job offer and i485 still pending and the employer is willing to sponsor h1b, do I have to return china or third country for the h1b visa?

Q2: if my i485 denied and got a job offer right around that, what would be the best strategy for me? Can I continue to finish my phd?

Q3: if my i485 denied and didn't have a job offer, what would be the best strategy for me? Can i continue to finish my phd or transfer to h4 etc.

Thanks very much for your inputs, xiaobaitu!