It is very common for a CPAP to be misconfigured or not to be the right size in the first place. You may want to ask a sleep tech for help. There is documentation online as well.
It's about 16, right on the edge of being considered "moderate". I have roughly the same number of conscious wakings with the machine as I do without.
I have already had the pressure dropped once. My main problem may be that I can't get enough air through my nose, so I have to breathe through my mouth. Using a chinstrap makes me feel like I am suffocating.
It is very common for a CPAP to be misconfigured or not to be the right size in the first place. You may want to ask a sleep tech for help. There is documentation online as well.