You can totally go 250km/h on the A5 from Frankfurt to Darmstadt, if traffic allows it. That wont always be possible, but typically if it isnt during work traffic, 160-200km/h is doable comfortably, even on other parts of the Autobahn

The longest unrestricted part that ive driven should be the A71, where you can go longer passages without restrictions, save for the tunnels.

Imo the discord works quite well. For mods the github repo us great and for most questions a diacord is enough. I like the fact that i can quickly share stuff and get answers. Forums always felt very clunky to me. I can use them, but the culture us often a bit shit, and then there are those that need registration to view posts or pictures. While those problems also apply to discord, i dont need a ton of accounts, i can somply join a server.

The instructions on the Web are pretty good, unless you start messing with Tons of mods, but thats your own fault.