Mouse acceleration is shit, and I wouldn't use it even for browsing the web. Acceleration off, adjust steering wheel compensation and mouse sensitivity (control panel).
In LFS it feels as if road cars response is quite progressive when compared to AC. In LFS I can throw the steering wheel around and feel that the response is "slow". In AC road cars want to respond RIGHT NOW, it feels very different around the centre of the axis. I don't know if that is because of tyre deformation, load sensitivity, weight transfer, physics loop resolution or what. Netkar was somewhere in between LFS and AC in that respect, from what I can remember.
There is no problem with freejoin, works for both server and client. Troy's server is offline, because it's a Linux server. There is no compatible Linux server for the current version of AC.