1. I do not have tire monitors or an engine computer so I am blissfully unaware of possible reading conflicts.
2. I do not have an engine brake. My exhaust brake works down to about 25mph and not over 65mph and I would expect the engine brake to do the same thing especially on a steep downgrade?
3. I believe my original safe combo was 0,0,0 or maybe 1,2,3. It is the traditional left three turns, stop, right two turns, stop, and left to stop. Mine is quite sensitive. Take it to a locksmith if you do not have a manual.
4. Steep upgrade with the mechanical cummins, I downshift the allison to maintain 2000 RPM (2300 max recommended) to keep the engine cooler in hot weather.
5. Steep downgrade I down shift to 4th or 3rd gear dependent on length, number oflanes and caution required..... (5th and 6th are just overdrive type gears)
6. Tire pressure. Weigh the coach axles and then reference the tire Manf charts for necessary air pressure on that axle. You senders may be set for the appropriate pressure and your installed pressure may not match. Try to determine and preferably add the required additional air to the tires before the vehicle is driven. The Air Pressure rises rapidly with ambient temps and tire motion.
7. Your House batteries may last a week if stored but not disconnected and not on shore power. Phantom loads inside the coach are common. The engine batteries should act like a car battery and be good for a month. My inside disconnect is for the house batteries. My battery compartment disconnect is for the chassis batteries. 12.2 Volts is the level at which charging is recommended to extend the life of your house batteries.
6. Your wiring problem sounds like a loose or shorting positive wire in that wire bunch since to my knowledge a ground wire would cause the wipers to not work. Try to obtain a CC wire schematic for your rig. I have found that to be indispenseable as time passes. When you have it. Label your fuse box schematic with the purpose of the wires passing to it. That save some on-the-spot time in diagnosis in the dark.