If the Gross Vehicle Weight Rating of the trailer doesn't bring the Gross Combined Weight Rating of the entire combination in excess of 26,000 lbs, you don't need a CDL for it.
Yes, you would. Without the trailer, you could operate it with either a Class A or Class B CDL.
The requirement for when a CDL is needed is not based on a vehicle's length.
If the truck and trailer are not equiped with air brakes. If the truck and trailer are not comercial vehicals.
Anything defined as a CMV will require a CDL, regardless. So if it's pulling a trailer, yes, it will require a CDL.
You can haul one without it.... so long as the GCWR of the truck/trailer combination doesn't exceed 26,000 lbs. with the trailer having a GVWR in excess of 10,000 lbs., a CDL isn't necessary.
Out of service, heavy fines, vehicle impounded.
No you do not need a CDL for this. You will need to have a license plate and registration for the trailer along with opperating tail and brake lights.
Yes. You need a CDL and a hazmat endorsement both. You're well above the allotted amount which can be transported without the tanker and hazmat endorsements.
Depends on which Class of CDL. A driver with a Class C CDL is not licensed on that vehicle. A driver with a Class B CDL can drive that combination only if the GVW of the trailer is less than 10,000 lbs. A driver with a Class A CDL can drive it.
If the Gross Combination Weight Rating of the two vehicles (power unit and trailer) is in excess of 26,000 lbs., then no.
Length does not determine whether or not a CDL is required.
The regulations for when a CDL is required has nothing to do with length.