When applying for a commercial license, the driver must demonstrate his ability to handle a truck for commercial purposes, and must have a good driving history.
Clean Legal Record - most companies require that their drivers have clean histories. Being convicted in the past for felonies is definitely a detriment. In particular, companies avoid drivers who have been convicted for heinous crimes, felonies involving the use of a motor vehicle, and driving while intoxicated or high on drugs

They want to know if you have any criminal record or mental illness or physical/medical problems that would keep you from getting a CDL or being bonded.

There are several medical conditions and medications that disqualify you from a CDL. IE: Diabetes that requires insulin injections, high blood pressure, narcotic use, prescribed or not prescribed.

Bonded is sort of like an insurance policy, or security clearance. If you are bonded, it means an insurance company is standing good for your honesty. You need to be bonded to haul certain commodities. IE: Money and other government commodities, other controlled substances, etc.

You do not need to be bonded to have a CDL and most drivers are never bonded. It is good to be bondable though.