A frequency has to be programmed into a channel for the radio channel to work.
The PMR446 unlicensed radios are approved for operation within the UK and most of Europe.
There is no definitive answer as radio signals can be adversely affected by obstructions such as buildings or topography. It is advisable to carry out a site test prior to any purchase.
No, because they operate on a completely different frequency bandwidth.
Not unless a channel on your radio has been programmed with the same frequency.
Coverage can be enhanced by the installation of a Repeater Base Unit connected to an external antenna.
Some users require several frequencies e.g. construction sites, hotels, distribution centers and airports. Manufacturers therefore produce radios to accommodate all scenarios.