I have Kobo glow and have some questions about registration and ebooks

First, my Kobo glow is in the U.S. When I go there Dec. 20, I'll be able to register it.

Here are my concerns:

I'm thinking of buying a few ebooks right now from Kobo.com BEFORE I register the Kobo.

(1) Will there be any problems later when I actually register my Kobo Glow?

(2) Can the calibre plugins handle the conversion of epubs bought from Kobo.com, so that I can read them on my other devices?



Thanks,
Don