I don’t think it would. IIRC, CB radios are type-certified, which means that the transmitter itself is licensed, rather than the operator (similar to FRS).

That said, these days the FCC gives absolutely zero shits about what happens on 11m, so I wouldn’t expect any knocks at the door if you modify a non-CB radio for use on CB channels.

You can, but the problem is that the radio chip is not designed for the 27Mhz, then you will generate an huge amount of spurious that will pollute other bands and wasting lot of power. I advise don't do that, just to avoid to interfere with some critical services.

Wrong frequency range - these handhelds are designed for 2m and 70cm, and CB is 11m. You'd have to do a lot of tricky hardware modification first, and then hook it up to a rather large antenna for a handheld.

In addition to it being technically illegal, you probably can't transmit well on CB without an external antenna and amplifier.