Rick,
You have some very serious issues going on that could be very dangerous. Use caution, as Joel pointed out, when working under your coach. First the air bags, sounds like the bags are not getting air because of air supply problems or ride height valves are not working, broken or not adjusted correctly.
My recommendation, based on your posts would be to have a professional diagnose your problem. Also, I would NOT drive your coach until this issue is resolved to the point of air bags filling with air and adjusted to the correct ride height. If my memory is correct on my 97 Monterrey is was 9.25" not 10". Anyway, the chassis manual should give you that measurement.
On the engine error code, does you coach have a Silverleaf display in the center of the dash? If so, you can read the codes from that unit. If not, buy yourself a Scangauge "D" unit at AutoZone, Advance Auto Parts or online and it will allow you to read the codes and reset the check engine light on your dash. With out knowing the codes, we cannot help you on your engine problem.
The cruise control issues I cannot address, just not something I remember or recall in my coach.
Good luck, keep us informed of your progress...