old pipes in the sink or tub upstairs
Temperature balance shower body needs to be adjusted
Mixer valve
You have to undo the aerator at the end of the faucet and clean the screen or plastic water saver out. It will be plugged with sand or sediment.
Most of the newer kitchen faucets have "flow restrictors" to limit water use.
The water valve under the sink is turned off or has gone bad. It is possible that there is a blockage in the faucet itself. I'd start by ensuring that the water valve is turned off, and take the faucet apart and look for anything out of the ordinary.
Possibly a pressure reducing valve installed after piping for first faucet, which would cause situation describing.
If water faucets upstairs and downstairs are turned fully on, you would be wasting a lot of water. Each faucet delivers about 3gpm under normal use. this kind of use would lower that figure considerably. If there was some kind of question involved here, it wasn't very apparent.
Yes, drinking water faucets do come in bronze. They are available from Home Depot, Lowe's, Walmart, and Amazon along with several other locations and stores.
Low water pressure or cold water main undersized.
Protecting your home against a hard freeze (32 degrees or lower) can prevent damage to water pipes and other systems within the home. Outside, keeping trees trimmed can prevent damage from falling branches onto your home. Cover or bring in plants that may be damaged by the cold. * For the water pipes, remove hoses from outside faucets. Use foam tubing or other materials to cover the pipes, particularly the water main. * Inside, leave faucets dripping, open cupboard doors under sinks so that the heat from the house will also keep that area somewhat warmer. * If the house is going to be empty, you will have to drain the faucets and turn off the water--that is more detail than provided here.
check for leaks
The shower valve needs to be repaired! As for the water not shutting off when you turned off the main that is also needing replacement when it shut of by turning on other faucets you were simply diverting the flow from the leaking main shut off.