Air pressure in each tire

Tires are ALWAYS checked when they're "cold" (not driven on) and necessary adjustments are made then. After that you can forget about tire pressure until the next time they're "cold" (undriven on) when you can check them again. It's really nowhere NEAR as critical as you seem to think. If you really try you can absolutely drive youself crazy, getting out to check tire pressure every time you turn a corner because the sun is hitting the tires at a different angle causing pressure increases or decreases and this is just not necessary. Other things that will cause air pressure to change is a significant change in altitude such as climbing into the mountains or dropping down to the planes. Weather conditions is another reason for daily changes in air pressure. Low pressure in the atmosphere will increase the pressure in your tires and visa versa. Rule is check them cold each day and make any necessary adjustments however MOST people will make that once a week or so when traveling and otherwise they just leave pressure alone.
Good luck and enjoy your new motorhome / Skip