I agree - the forced move is good, but still frustrating!
I have not migrated info over, nor do I feel I have "the easiest" answer yet. (Right now, the leading method seems to be convert my self-hosted/ftp site to a blogspot site, THEN use the WP import tool.)
Meanwhile, I do have WP set up and running, but there are a few problems I'm trying to overcome first that may cause problems during migration. (Can't get .htaccess & permissions working correctly! - any experts reading this and have pointers?!)
To answer some of your other questions:
I'm keeping the same URL, although the exact page my blog is on will be changing. but I do have WP saved in the main/root directory of that URL. My data will remain in the same directory, although different folders I'd presume?
Best of luck! Do let me know once you dive into it and how it goes; I'll do the same. hoping it's a productive weekend :)