All metals are conductive. Some better than others. Aluminum happens to be pretty awesome.
For checking spark, I highly recommend an adjustable gap spark tester.
As far as spinning the engine, you can have a friend pedal like crazy for you. Or, (and I know the debate will rage) you can spin the engine with a drill. You gotta be careful about stripping threads and whatnot, but with the spark plug out and no compression, it's not too risky.