Win 8 to Win 8.1 upgrade SkyDrive migration Questions

Some pre Pre-emptive  basic questions about the up coming Win 8 to Win 8.1 upgrade SkyDrive migration path

At present Windows 8 installed and the SkyDrive desktop app installed all works well  -  I login to windows 8 using a local machine account (Not the Microsoft account) this is how I originally installed windows 8

My worries are, that I gather you have no choice when upgrading to windows 8.1 but to use a Microsoft account -- this is not a problem as I can use existing one used for SkyDrive desktop app.

BUT ? in the process of upgrading and signing in with a Microsoft account is win 8.1 intuitive enough not to junk all files and photos in my present SkyDrive folder being that I would assume it creates another account ?  

Would the built in -- integrated SkyDrive sync back down from cloud my files etc. ?

Or sync up none    ?

Yes I will do a back up of my present SkyDrive local folders -- but would like to know some answers before possible hours of upload  or hassle factor

there seems to be no clear definitive information for people that presently use win 8 and SkyDrive desktop signed in with local pc account

Thanks in advance for any insight from anyone