I believe inflating tires to / close to max sidewall press listed and taking some load off is a good thing... certainly can't think of any reason it could hurt and some where it helps.
HWH says OK to store with leveling jacks extended. I prefer to use block under retracted jacks so they are supported on jacks when air suspension dumped. Best to exercise jacks periodically.
I'm sure you will find many thoughts, opinions & practices... ultimately you will need to decide which you prefer.
Don & Marge
'13 Newmar Ventana 3433 - '14 CR-V TOAD
'03 Winnebago Adventurer 31Y - SOLD