So, some possible suggestions:

1. Use of VPN's to connect each client. This should reduce most of the attacks. Obviously changes to the existing network code should also scale to something a little larger than 16 players, but ROME wasn't built in a day as they say.
2. Issue keys to people for play. This can be automated at connection time, and tied to a persons phone. So a Phone or a FOB will be required. Fobs are pretty cheap, and Phones, well will require someone to write an app.
3. Charge to play. Doesn't have to be a lot, but something to cover the infrastructure costs of hosting the infrastructure to do the above, which will be complex.
4. You will need a team, probably of 2 people, one to write the network code and the other to write the client/app software for the phones.
5. Development time would probably work out to around 15-20 months if you had two guys working full time.

From what I have seen so far the requirements do not seem to be too onerous, so start a kickstart campaign to get about 500K to get the ball rolling. I mean if Star Citizen can produce basically nothing for hundreds of millions, it shouldn't be too hard to get a half a million from somewhere for new infrastructure and code for the game.

I would really like FAF too succeed. Mainly due to the fact it brings back memories.

This other is because I like to see PitViperX get microwaved to the face.