Problems with endurance races can be easily fixed. We need something at server-side to block all flags and other HUD info. Then we can handle everything with InSim. Let's say "/nohud=yes" in server config.
Linux is not Windows. Needed updates can be installed without reboot. Kernel updates could be done, but I personally install them rarely. Once per year, sometimes once per 2-years. Server should work constantly.
I see you have problems with Polish characters Just change them removing special parts, like: ś to s, ą to a, ć to c. I can make you replace array for that.
Server flags in PRISM are 1740. Any button from any plugin won't display. I know that is very small info about problem, but it happens first time to me and everything else is ok.
Zombie Mod it's great. It's not very hard to implement with XI4N. LRS will be hard to do like you said, Hillclimb - personally it's bad idea (nothing interesting), RCWT - great!
I hope when you finish new tyre psychics you will take few suggestions from us about InSim and we will see them faster than psychics, ok?
We need tweaking by InSim to make LFS alive. I dream about InSim packets that can modify car/engine/clutch damage and tyre properties to allow keeping car state between sessions.
First psychics, than small improvements on InSim side.
There was LiveGap somewhere on the forum. Making such thing that you said it's getting race time on everyone's split/lap and update a button on screen.