Is UHF better than VHF for this radio's use?

UHF generally penetrates walls and buildings better, which suits indoor and urban work. VHF reaches farther in open, flat terrain. For warehouses, stores and events, UHF is the usual pick.

How far will it transmit?

No reliable range figure is published for this model. UHF handhelds typically cover a building or a few blocks outdoors, and range drops sharply indoors and in dense areas.

Does it work with standard headsets and earpieces?

Compatibility depends on the connector, which is not documented here. Check the plug type before buying an earpiece or speaker mic, since business radios use several different connectors.

Can I use it without a license?

In the US, business UHF radios generally require an FCC license for the frequencies used. Confirm the frequency band and licensing before putting it into service.

Is it a good choice over a Motorola or Kenwood business radio?

Those brands publish channel counts, power ratings and battery specs and have wide accessory support. This Procom is a simpler option, so weigh the missing documentation against your need for a basic short-range radio.