There are no such things as "stupid" questions. However if you think your question is a bit stupid, then this is the right place for you to post it. Please stick to easy to-the-point questions that you feel people can answer fast. For long and complicated questions prefer the other forums within the support section. Before you post please read how to get help
Installing one more distro should not trash home. But if it's pretty close, but still very different (and yes this makes sense if you ponder it a while) it may trash settings in files by the same name, because home is "touched" during install
Oh - this is rather confusing taken literally
By changing the permissions in Fstab I am able to access the files from XP.
I hope you mean you are able to access the "XP files" from Linux as what ever you do in fstab does not change anything in XP
Don't fix it if it ain't broken, don't break it if you can't fix it
No. Having changed the permissions on the FAT32 partition on my Mint machine has now allowed me to open files in it from my XP machine across the network. The only difference which I now have from PcLinux is when trying to open Microsoft office files on the XP machine from Mint the splash screen for Open Office is displayed but the files do not open, I have had this problem a couple of years ago on another Linux distro but cannot remember what the solution was. I have posted this question under software.