AFAIK, the simple answer to the last question is you don’t have to “safely disconnect” in MTP mode (how would you…go to the Control Panel…?), but out of habit I do when in MSC mode (it could be in the process of writing to the Clip’s drive). But since the Clip is solid-state, my sense is the worst that happens is you reformat the Clip and put your music back on it.
-Matt
