Yep, fair enough. Maybe, with more content being added to S3, people will buy the S3 license and the devs could get the chance to upgrade the engine. The replay and spectator netcode is just terrible and hides so much info.
Project Cars 2 works flawlessly with 32 cars on grid. I doubt that 40 - 50 would cause any more fps drops in LFS as the graphics are much much simpler. If you run shaders, then probably. With default graphics? Nah.
Cruise servers are arguably the most popular servers in LFS and extra slots for them wouldn't hurt. Increases traffic flow, would be great on both smaller and bigger maps. Same for event servers. More players, more chaos. Race servers can keep their slots, but with the graphics/weather upgrade coming, endurance races will be more popular and those are much more fun with more players, so again. Depends on what you want, but in general, more slots = better.
I hope it'll be better than that. I mean, sure, it's better than what we have now - nothing - but it's just a 3D picture moving and rotating across the sky (the clouds/sky).