If it's a class of vehicle which is rated at under 26,000 lbs. GVWR and not carrying either more than 15 passengers or hazardous material, or a recreational vehicle, then normally, no. However, some states may require it regardless, but will have signs posted at ports of entry indicating such.
Interstate weigh stations require any large truck to stop at the stations when they are open and active. A dump truck qualifies as a large truck that would need to stop.
If it is used for commercial purposes in interstate or intrastate commerce then yes you do have to cross scales at weight stations. You are also subject to the same laws of a typical commercial vehicle. If it's used as a private vehicle then no.
In order to get a truck you either need to buy it from a private dealer or a certified dealer.
They wouldn't need to. "Tare weight" is the weight of your empty truck. To get a tare weight, you just weigh the empty truck.
Need to know the model and configuration in order to answer this.
If your truck is powerful enough and can handle the work and weight of a plow, then yes. You will likely need traction devices and extra weight on the rear end though.
Need to know the exact model and configuration in order to answer this. A 26k GVW box truck and a 33K dump truck aren't going to have the same tare weight.
Because they not only need to support the weight of the truck itself - but also the load the truck is carrying.
That depends on the Gross Vehicle Weight Rating of the truck, not on the length.
All commercial trucks are subject to total vehicle weight limits and also weight limits per axle. The scales are there to enforce these weight limits.
At U-Haul, the smallest truck that will hold 40 cubic yards (1,080 cubic feet) is a 24-foot truck. You will also need to check the weight capacity.
No a used mail truck does not need to be used for private use only. It can be used for commercial purposes.