H1b Extn + Amendment in premium

[jhariharan]

My current I94 (H1b) is valid till sept 2019. I have to apply H1b extn + Amendment and im planning for premium processing. I have below 2 questions if my case is denied by USCIS

1. Can i stay and work till sept since my i94 is valid till sept?
2. Can i re apply for h1b extn + Amendment?