A:AnswerFollow this. (I know that it says “updating,” but that translates over to flashing.)
The board should be fine as it supports third gen Ryzen.
If you have questions, comment below and I’ll try to help you out.
https://www.gamersnexus.net/guides/1572-how-to-flash-bios-on-asus-board
A:AnswerNo this won't work with intel it's only for AMD. There is an Intel version of this tho ... Look for Asus ROG STRIX Z490E for a similar style Intel mobo.
A:AnswerMost part are compatible up to an extent. Usually it is recommended to keep parts within the same generation for most combability. You would need to have more information on your other parts in your computer, as those could impact your new graphics cards processing. The last thing I would add is that there is currently a shortage of graphics cards. Normally a budget of 700 would get you a good mid tier GPU but due to shortage and scalping that is not the case. Have some patience and check with forums or ask a professional on the matter.