Storing your sleeping bag: If you have the space and your cellar is free from dampness, then sure, hang your bag as suggested above. But do protect it from dust and dirt. Having said this, you can also store your bag inside the large cotton or mesh bag that comes with it. No problem at all, and no, it won't damage your bag's loft either. Just make sure that you store your bag clean and dry -- and in a cool, dry place.
Storing your tent/tarp/bivy: First, ignore the myths that get repeated ad nauseum about folding vs. stuffing. You can either hang them or store them in their stuff sacks -- either rolled, folded, or simply stuffed. Makes NO difference whatsoever.
There are really only three conditions for proper storage - namely, that you store your tent/tarp/bivy:
1. thoroughly clean
2. thoroughly dry
3. in a cool dry place away from sunlight
Moisture can result in molds whereas sunlight (UV) can break down the nylon or polyester fabric. Stored clean, cool and dry, your gear should last for many years. Hope this helps.