This is a social problem, not a technical one. Solving a social problem is always harder than finding a way to transmute the issue into the realm of the technical.
Were I you I would use Knoppix (if you run Gentoo already, this will be a breeze). You can boot into Knoppix, which is entirely self-contained and won't even access the taxpayer's harddrive. If you search these forums you'll quickly find resources for linux FRC programming tools... just make
a custom knoppix distro with these tools!
This could actually be extremely useful now that I think about it! You don't need to install any software, your code files could be stored on a USB key. You can't mess really screw anything up if you don't mount any non-volatile drives...
Tech people are happy because you aren't touching their precious harddrive, you are happy because you don't have to putter about within their comfort zone.
To all of you who are pulling the righteous indignation bit, this issue is not as cut and dry morally as I take you to be making it out to be. After all, if the taxpayer is funding incompetant IT staff that compensate through the implemenation of draconian policies hampering the education of said taxpayer's children, there is a whole chain of wrongdoing before the level of the student. That said, two wrongs certainly don't make a right and the last thing you want to do is give them a legally valid reason to make an example of you (which altering their hardware would most certainly be).