Just having a truck under CDL doesn't mean there aren't other rules.
If you drive a truck under 26,000K lbs, sure, the CDL requirement is waived, but the daily inspections and health (physical) card is not. (I know, to the tune of a 2 hour inspection and $300 fine for no physical card) The law may vary by state as far as enforcement, but CDL is a fed DOT reg, not a state one. If you have time, drop into 2 different state licensing offices and pick up the cdl study booklet. you will find them to be a word for word copy of each other.
Remember if you do decide to go CDL lisence and truck, you must keep a log book unless your company has a log waiver issued by the DOT, which limits you to a range of 100 air miles per day. again, local enforcement plays a role here. Don't forget that each company who hires CDL driversmust (by fed req's) have an approved system of random drug testing in use for their drivers.
imo, this is why the 26-30K lbs gross trucks have kinda fallen from favor. most companies will either run under CDL limits (up to 25.9K lb gross) or go all the way since they fall within the reg limits, and run chip trucks of 35-50K lb gross for larger loads and less dumping runs.
I encourage you to investigate the fed, state, and local DOT laws on your own and to talk to your accountant to determinethe best situation for you and your company. most state DOT offices/officers are more than happy to talk with you concerning the laws and regulations.
-Ralph