It would be a lot of work to do that - NeoFPS isn't currently set up for multiplayer and to get it properly working would require modifying some of the code. I'm looking at ways to improve the architecture for that, but it will be towards the end of the year before that will make a difference for you, at the earliest.
Similar goes for the third person body at this time. It's very much a body attached to a first person setup instead of a first person camera attached to a full body character. I'm adding AI soon, and doing some work for their body and weapon setup that should feed back into future third person / multiplayer solutions later in the year.
Sorry I don't have an easier reply for that just yet. As new features come online, the situation should improve drastically there.