Yes. Always.
No
-spacespace- No
Yes. To have an active CDL, you need a current DOT physical, always.
No, you do not.
Yes. You can identify as "intrastate exempted" without one, but you won't be able to operate a CMV until you have a valid DOT medical card.
When you go to the DMV to get your CDL, you'll be expected to show either your DOT medical card, or the DOT physical long form. Additionally, any employer hiring you as a CMV operator is going to require you to present your DOT physical card, and possibly the long form physical, as well.
You need that in EVERY state.
Typically, two years. Drivers over 55 (IIRC) or who had to be waivered on the physical requirements must update them annually.
You must have a current DOT medical card to maintain an active CDL in EVERY state. That is a federal law.
Typically, two years. I believe a CDL driver over 55 must update them annually.
It depends on what the nature of the disability is. You need to be able to obtain a DOT medical card in order to get a CDL - some disabilities will prevent this, while others will not.
Not only any public roadway. This vehicle requires an active CDL, and if your DOT physical is expired, your CDL is null and void.