Galvanized pipes when they start to degrade can reduce their diameter to barely a pencil and can actually nearly block off the available flow before they start to leak because all the iron has changed into rust.
Trying to suck more water than the pipe can supply can increase the wear and could cause the pump to fail if it gets starved. Water pressure with no flow is not a good indication of anything...course, it needs to start out good. See what the flow you get with the pump off.
A booster pump only works well and lasts long if it can get all the supply it needs. SOmetimes, you may need to fill a tank and pump from there to ensure you have enough volume. Replacing the supply pipes, assuming they're large enough for your desired flow should help lots. Now, some places have quite low water pressure and a pump could still help.