H Visas: H1b Transfer After Rfe on Extension

Hi,

My current H1B visa got expired on 14th Aug 2017. My employer has filed extension before that but received RFE which is due on 21st Sept 2017.
Now I have following questions:-

1. If I get new job offer then can I transfer H1B to new employer while my current extension RFE is not responded yet.
2. If I apply for H1 transfer before RFE due date (21st Sept) and my extension gets denial or if its withdrawn by employer then will I be out of status?
3. If I don't file H1 transfer then can I file H4 dependent visa while RFE is pending?

Thanks in advance.

H Visas: H1b Transfer After Rfe on Extension