Please help me with some questions about flash drives?

We recently began using flash drives at work and then told we could only use a certain computer. This particular computer doesn't have Microsoft Word, and my many requests for it apparently falls on deaf ears going on 4 months now. So I bought a flash drive of my own to maybe remedy that problem and play around with it a bit. I found and installed portable open office for work, then decided to put some little games, a file manager, a win-zip type program, calendar program, and a media player. Boring stuff for now, but never having owned one before, i'm just having fun learning about it. However, I do have questions that Google apparently can't answer for me. If you could help me with these I would appreciate it.

I used my home computer which has Windows Vista to load my copy of Open Office, but the computers at work have Windows XP. So will there be a compatibility issue running the Open Office at work? Should I have it run in compatibility mode for XP just in case?

Another question is- When you install an app do you have to keep the original zip files on the flash drive/computer hard drive or are they necessary in order to use the programs on other computers? I''ve placed them in a separate folder on my FD for now just to tidy up at least.

Thanks for any help, it's much appreciated!!!