If it's transporting a quantity of hazardous materials which requires placards to be displayed, yes. If it's a bus designed to transport more than 15 persons, yes. If it's attached to a trailer which itself has a GVW of more than 10,000 lbs., yes, UNLESS it falls under the farm truck, emergency vehicle, recreational vehicle, or military vehicle exemptions.
Otherwise, no.
No.
In some instances, yes.
If the Gross Vehicle Weight Rating - not the actual laden weight at the time - is under 26,000 lbs., then no. You will, however, need a current and valid DOT medical card.
No. Such an endorsement does not exist for US licenses.
Only if it's a: transporting hazardous materials or b: a bus designed to transport more than 15 persons (including the driver).
To answer you we need to know what country's traffic regulations you are asking about.
Not unless it's a bus designed to transport more than 15 passengers (including the driver).
Air brakes have absolutely ZERO determination in whether or not a vehicle requires a CDL.
You need to call your state's DMV on this. I know I have seen the F750 registered as a 26k truck before, but the laws on this will vary by state.
Only if it's designed to carry more than 15 passengers (including the driver), or transporting an amount of hazardous material that it requires the display of placards under FMCSR.
Only if it's transporting 16 or more persons (including the driver) or sufficient quantities of hazardous material to require placarding with HAZMAT warning signs.
The air brakes are irrelevant. And you'd need a medical card in that instance if you were doing interstate operations, but not intrastate operations.