Can I harm myself with any of the Tools?
Well, anything made of metal will hurt if thrown hard enough, but the fields of the tools can only work in a beneficial way. Some of Slim's early inventions had safety issues, particularly the powered ones (read his book for more details), but taking them back to the drawing board and discovering that twisting the wire removed the problem of polarity, meant that the tools we have today are at their very worst, harmless.