A tub faucet acts as a shower and can be used to bath in the bath tub. It is a pressure valve which makes the flow of water through it constant and gives a nice shower.
Yes
yes
Faucet side.
Most of them are in the wall. The other would be a deck mount, which is mounted to the fiberglass tub deck and uses a Roman Tub Faucet.
It depends on the make of the faucets.
A Roman tub faucet does have good water pressure because it is made to do that. How good this is depends on how other brands perform in this area.
By un surrounding it
Maybe the kitchen is further away and on smaller pipe.
It may be easier and cheaper to buy a whole new faucet.
Defective faucet or foreign material got into faucet at installation. Improper installation.
Defective divertor
YES