Not sure what you mean by "a while," but if you mean you're pulling over for lunch, it wouldn't be necessary. And my understanding is that slides should be retracted for storage, so that would seem to indicate extending them when you are not using them is not called for for any length of time. I'd see not reason to set stabilizers if you're properly blocked. But I still have a lot to learn and stand to be corrected.
'11 Eagle 320RLDS
'02 Ford F350 DRW 7.3 PSD, PacBrake,
6.0 cooler, Ford AIS, Isspro trans. gauge
Flashpaq tuner, AirLift airbags
2013 Ford Expedition King Ranch
While most of the answer would be that it's up to the individual to have his/her rig sitting "for a while" with slides in/out and levelers/jacks down or up. There's somewhat logic for each scenario. My thoughts are, when our rig is parked at home, and it's going to there for a while, as in a week, a month, 3 months (rare), the jacks go down and the the rig is leveled. Now, it sits on an almost perfectly level slab so, the jacks don't have to be too out of contortion for the rig to sit level at home. And, I'm not one of those that worries about "pressure" on the leveling system. It's designed to handle that pressure.
As for your slides, well again, it's up to the individual. If, you're in and out of that rig, while it's being stored, and you're cleaning it, or working on stuff or changing the loading of the cabinets or whatever, then the slides in the out position are of great benefit. However, by being in the out position, you're exposing the seals and tops of the slides to extra dirt, debris and depending on whether the rig is in the sun or not, you're subjecting those portions of the slide to wear and tear of the elements that it would not normally be subject to unless you're using the coach.
Again, you look at what you think is of value here. I value taking the load off the suspension parts, air bags, tires etc so, my jacks are handling at least half the weight of the coach, if not most. Our slides are in, unless she or I need them out for whatever reason. Then, they go out, we do what we need to do, even for a day or few, then, they go back in. It's a preference thing.
Scott and Karla SDFD RETIRED
2004 Itasca Horizon, 36GD Slate Blue 330 CAT
2011 GMC Sierra 1500 Ext Cab 4x4 Toad 2008 Caliente Red LVL II GL 1800 Goldwing KI60ND
It is up to you. We had an RV pad installed at the house so when we are not camping we can still use it. Our jacks are down and slides are out..
Todd, Shirley, and the "Maddawgs" min-pins Precious and Buster Brown
2011 Itasca Cambria 30C
2011 Demco KarKaddy 460SS
TST 507 RV TPMS
"if there is anything left when we are gone, then we miscalculated"