Depends on the GVWR of the trailer, the GCWR of the entire combination, and its use.
Depends on the GVW of the trailer and the Gross Combined Weight Rating of the truck and trailer.
No, you don't. RVs are exempted from CDL requirements. Your state, however, may require that you upgrade your licence if the vehicle is over 26,000 lbs. GVWR.
For private, recreational use, no. And this applies to all states.
Not necessarily, but specifics matter in regard to this question.
The requirement for when a CDL is needed is not based on a vehicle's length.
IF it is for commercial/business purposes and IFthe trailer and tow vehicle come up to a Gross Combination Weight Rating in excess of 26,000 lbs., then yes, you need a Class A CDL.
If the Gross Combined Weight Rating of the truck and trailer is in excess of 26,000 lbs, yes.
Only if you're transporting is as a third party carrier. Recreational vehicles are exempt from CDL requirements. However, your state may have additional requirements for non-CDL vehicles in excess of 26,000 lbs. Gross Vehicle Weight Rating/Gross Combination Weight Rating. You need to inquire with the DMV in your home state about this.
If it's a commercial use vehicle and the Gross Vehicle Weight Rating of the tow vehicle and of the trailer combine to make a Gross Combination Weight Rating in excess of 26,000 lbs., then yes, a CDL is required.
GVWR of the trailer, GCWR of the combination of the two vehicles, and usage matter. We'd need to know this in order to ensure an accurate answer to this question.
Anything defined as a CMV will require a CDL, regardless. So if it's pulling a trailer, yes, it will require a CDL.
The length doesn't matter as much as the Gross Vehicle Weight Rating of the trailer and the Gross Combined Weight Rating of the combination of vehicle + trailer, as well as its use.