I do not have an official answer for you, but I wipe all but battery stats just to be sure.
And it is easy, I been jumping around on ROMS. The hardest part is setting homescreens, reloading all the apps and remembering to back up certain things and restoring on the new ROM. That is what is killing me and wearing me out.
Just remember, first boot after install takes a long time. And if you use the FIRST build 2 that he has out there, screen brightness will be an issue.
Might want to use one of the nightly builds.
encounterpc : index of /bmc08gt/shadow/nightlies
Also if you do not want the soft keys, there is a frame-res.apk that you can download, then copy to the zip file under system/framework/ that will change it so you do not have softkeys since you have physical ones on the DX.
I have been going the extra step and adding my ringtones under system/media/audio/ringtones so I don't have to copy them later.