2. Reinstalling it on the same computer is not the same as installing it on a different computer
3. The limit to one computer only applies to OEM keys, I think. That's probably what you're dealing with here, but it's worth noting anyway.
4. DRM is stupid and it may prevent you from reinstalling on the same computer anyway. A lot of people get angry at this and just crack the OS instead because by the terms of the license they should be able to reinstall on the same computer.
I just use it for programming stuff. I put the whole visual studio project in the mega folder on my computer and work from there. The client takes care of the uploading for me.
kinda sucks that it uploads the binary folder too, but meh I have the bandwidth and it's too much work to compile to a different location
I'm not too sure the program will let you delete from the local machine without also deleting from their server... the files will still be in the rubbish bin or whatever it's called, but probably not permanently.