Strangely enough I found my Torx-15 driver at a country fayre which had trade stalls set up at it. It was one of these el-cheapo tools stalls and I got the driver for something ridiculously cheap like 50p. Maybe check out local markets or something?

I have found that a case splitting tool is not necessary - after un-doing the screws, hold the Mac just above something soft like a towel or cushion and shake it gently and generally the case will seperate. Sometimes the front bezel needs to be pulled a bit but I have never had a compact that has been especially difficult to open.

As for the CRT, it is best to leave the Mac sitting for a day or two to discharge the CRT. So long as you are careful when working inside it there is little risk of being zapped, basically just don't have it plugged in and switched on when working around the CRT.