Backing the limbs down isn't going to hurt anything, but about 5 turns and then write that down on a piece of masking tape and attach it to the bow somewhere. However, leaving the bow at your shooting weight isn't going to hurt either. From my experience most bows can be left at shooting weight and the limbs will only lose about 2# of draw weight over ten years, and knowing more about things these days that may have been due simply to the rigging creeping.
Yes, keep it in a case in a place that won't get hot or damp. Hanging on a hook is OK, but don't lean it anywhere that will cause pressure on the limbs or cams.
It is not necessary to lube anything. The bearing in the cams are factory lubed and sealed so adding lube to these is a waste of time. Yes, wax the string/cables and work it into the strands but you don't want to just glob it on the outside. It doesn't do any good there. Do it once and done. The wax does not just disappear over time.
Frankly, other than waxing the rigging most bows are just about maintenance free.
If You're Not Living on the Edge You're Taking Up Too Much Space
Martin/Rytera Staff Shooter
PSAA Life member, UBP Life member
PADI AOW Diver