RE: paying somebody to monitor the faucet: good idea, although I like the idea of some kind of "community watch" more. And monitoring the Faucet is an all-day-and-night, all-the-time kind of job. And if the scammers are willing to try to drain the faucet slowly then they could create accounts with more realistic-looking names and would be able to sneak by the monitors...
RE: just using testnet coins: I worry about people starting to trade testnet coins, giving them real value. Giving lots of newbies who don't really understand bitcoin testnet coins seems like a really good way to make that happen!
RE: proof-of-work before getting coins: Interesting idea! Some JavaScript in-the-browser proof-of-work that required keeping the 'get some' page open for a minute or six might make the cost to the scammers high enough that the bitcoin reward wouldn't be worth it.
RE: looking at the google account creation date: that information isn't available to the Faucet's code (unless I'm missing something in the Google App Engine API).