There could be a solution for the input lag issue. At least it improves things a lot with me.
Get the Sharp mod from Juls, copy and paste controller default folder in your game directory. It's actually the same as Shift1 (as far as I know, to confirm). Copy and paste dinput8.dll too.
I got a Fanatec GT3 RS V2, but it should work with Logitech wheels as well. It reduces input lag a lot, and improves FFB too. I got far better feelings with this tweak.
Try it and tell if it worked for you.
Sorry for my poor english...