Very good point about the genesis block.
Unfortunately, I'm not exactly sure HOW to generate a valid genesis block; I can tweak the data but need to generate a valid block hash... hmm, I see some time in gdb in my near future...
RE: changing the protocol version: Good Idea, too. Every wire protocol message starts with the bytes '{ 0xf9, 0xbe, 0xb4, 0xd9 }', I'll tweak that in the TEST code so TEST and production clients can't talk to each other even if they manage to get connected.