How much money I invested into Murnatan will tell you nothing. It was 1 500 000,- kč - it is 69 858 USD. For someone from America it would be nothing. For me in Czech Republic it is too much. I never had such money on my bank account. My maximum on my bank account was commonly about 50 000,- kč. To have such money for game was possible only because I got good work (paid right about 50k monthly) and I spent all to my team. Over day I was working in the work then I come home and work on the game until night.
If you imagine that we was working 4-5 years with that money as a team, then it is something unbelievable.
I never like NS2. For the first look it looks similar, but it is quite different game.
About furry models - In the final Murnatan version will be possible to mod the game and replace aliens, weapons, sound to what you want - so even to the Tremulous models (prepared for Unreal Engine). Aliens visual is not the problem. Problem is that there is no AI bots. AI bots are not there because it take time to create them - do too much changes, upgrade to recent UE version and that is complicated. Probably would be better to rewrite game from C++ to Blueprints only, because I do not know C++ and I cannot pay to anyone. And that will take time and time are money and I do not have money.
it's not that difficult to implement quake engine style air physics into other game engines
Actually it is difficult. If you want to have similar behaviour like in Q3 engine, then almost everything is problem. Speeds, sizes, collisions.
But something you can do as a start is an alternative to the forums: Who uses simple machine style forums in this day and age? Discord is a common solution, although there are quite a number of downfalls with it including the 100 server limit, but it's great for pick-up-game bots. If you ever do create a discord server and need help managing it, let me know.
We have discord. But that is only chat. Current social networks works only for this moment. Everything older is forgotten and cannot be found. Forum like this is organized and contains everything easilly searchable thanks to topics.