Finally feel like I can function pretty well and even manage to hit high speeds on motorways.
1. My setup is keyboard for steering, mouse for look only.
2. I adjust the Steering sensitivity up and down as I play.
(a) If I am in a truck with no trailer I'll adjust it about 20% (I count "zero" as all the way to the left, and 100 as all way to right). This gives me enough responsiveness in the A and D keys to make somewhat quick turns.
(b) If I have a trailer but I'm not on or nearing getting on a main highway (higher speed road) I'll also put it at about 20%. Maybe 15% for departure after hooking up, 25% for arrival and getting ready to finagle it into the dock. Maybe even go up to 30% for parking the trailer at the dock, but not for roads where speed is 30km or faster.
(c) For highways and especially motorways (speeds up to 110 km/h) I adjust it as close to zero as I can get. This allows me to actually function at high speed, pass other rigs with a close shoulder, etc. However, at high speed with sensitivity too high, you'll fishtail and bounce off everything.
3. I initially played it with simple auto transmission, but now I'm playing sequential and I use Mouse left for ups shift and mouse right for down shift. Reverse is on bottom, then up one is neutral, then up one is 1st and so on. Mouse movement is look. W accelerator, S brake.
Other than that I pretty much play with stock settings.
At first driving with keyboard to steer seemed impossible, but I kept fiddling and that is what I came up with. I can generally manage a ~450km trip and suffer negligible damage to my cargo and truck.