Guess the dangers are bricking your phone (not likely but possible). You will also need to revert back to nodo later before you install the official update, so make sure to keep the backup the tool creates safe.
I'm in college, so I have a student email, and used that to get a free dev account for the time being.
That's a totally different process I guess, but I tried it once and the back up failed. I have a Focus with an Extra 16 GB card, so I went back and deleted all my music.
That's an extra tip. Delete everything you can resync before your back up so the back up takes less time and less chance of a screw up. Why do I need to be backing up my music when I already have it backed up every which way to Tuesday?