It's time to change the diaphram water tank. Does a larger capacity tank mean that the pump will not have to come on as often? Yes it does, or get a Cycle Stop Valve
I have a 20/40 pressure switch at present. The tank comes with 30 lbs of pressure installed. Do I have to let out 10 lbs to match my switch? Let out 12 pounds to make the pressure in the tank 18 lbs.
Will a 40/60 switch result in more water pressure? Yes, but air the tank up to 38 lbs.
Is there anything special I need to know about installing a new tank? Should be a direct replacement all but the air pressure.