icloud backup ios 9.0 Beta2

Hi there, I'm running ios 9.0 Beta 2 on both iphone and ipad. Two queries

1. I've just received a cloud storage almost full message which has never happened previously. The icloud backup on my devices shows a different date/time to what is being displayed in icloud.com. Why?
2. I didn't take a back up of ios prior to taking the public beta. Silly yes I know. However am I able to revert to the non-beta ios 9.0 when it's released without having to start from scratch? ios beta is just too buggy for my liking, especially third party app crashes.

Thanks in advance.