Paul,
I will try to answer your questions;
1. Most but not all coaches with an air suspension will have a dump switch. It is usually located in the control panel for the leveling system, but not always.
2. I could not find any information on how many air bags were used on the 2001 Monterey, so we will have to wait for a 2001 Monterey owner, or maybe Roy Muller will pitch in with the answer here.
3. You do not set the air bag pressure, but you do set the standing height for the suspension. If the height is correct, the pressure is of no concern because as the weight of the coach changes with the addition or subtraction of fuel, water, or cargo the air pressure will increase or decrease as necessary to maintain the correct height. If you are not familiar with suspension service, you should leave any repairs to a professional because it can be dangerous, especially if you turn something the wrong way and let the coach down on yourself.
If the coach leans to one side as the air leaks down, that means that the low side is leaking faster than than the other side that still has some air pressure in the air bags. If the air bags leak down in a couple of days, you should try to locate the leak and repair it, although a slow leak can be very difficult to locate.
Gerald