Driving question #2 (see details)

I don’t see why. The only bad part of transport trucks is hills slow you down. So long as you have a truck lane, I’ll be right in there with you hoping not to hold you up. ( see your other question)

They do have separate posted limits in parts of the US, I’ve noticed (possibly in Montana?). As well as separate limits at night. I imagine that must be difficult to enforce.

I don’t particularly have a strong feeling about it either way. Slower trucks might slow others down, but they might also be easier to pass. Potato, potato.

No, not unless they have their own lane. If they are going 60 mph on a road signed for 70 mph (that is, the truck speed limit is 60) then that messes up everyone’s drive in the slow lane, and it is a traffic distraction in the passing lane.

Bad idea.

It would depend very much on the condition and capacity of the road. There are unquestionably roads traversing terrain where a 70 mph speed limit for a passenger vehicle would mean certain death for the driver of a fully laden 18 wheeler.

In the UK the speed limit for trailer vehicles (articulated lorries and cars pulling caravans are in this category) is 60 mph on dual carriageways (eg motorways). it is 50 mph on roads without a central barrier. The speed for cars, motorbikes and vans is 70 and 60 mph respectively. I understood the reason for this was the risk of snaking and then jack-knifing at high speeds. The speed is even lower on the smaller roads because the vehicles will be much closer together. The relative speed of two vehicles passing in opposite directions is high and the air turbulence could cause snaking.

No. Nor can I see why any well trained, alert trucker should have to do so, no matter what the conditions.