Its possible to make nastyhosts service with public database where can anyone put suspicions IPs and it will be updated automatically to all users who run nastyhosts protection?
It's possible. However we won't add this to nastyhosts itself, it's too easy to abuse it (someone could just add 0.0.0.0/0 network and effectively break all faucets using such a service), a heavy moderation would be needed.
I think someone has already mentioned this problem but - the problem is with timer. Faucet give some satoshis every 180 minutes. But visitors say that after 3 hours thay can't collect satoshi because they see "You have to wait 179 minutes" as if they've already claim satoshi
That's always a problem with a reverse proxy. All users share IP addresses of a reverse proxy, so if one user claim, they all have the timer.