I knew you could download the books via the BN website, but wanted to test the apps to make sure they were still working since some people were "concerned."
I did download the Kobo Extended Plugin and have it installed. I haven't looked at creating shelves or anything yet. I took the time to get covers the way I wanted them and make sure the metadata was updated with series info (so I'll be able to see what's next without looking at reading orders online
) I am planning to only use the one device so don't need to keep separate libraries in Calibre.
As for the other stuff you mentioned, I probably won't upgrade the internal SD card but will make sure I back it up just in case.