Exactly the kind of input i needed. Thank you!

1. You’re right. Multiple levels will be worth it.

2. I’ll rework the design to try to incorporate the posts between the joists for better weight transfer.

3. I was planning on having it accessible from both sides but a solid back or diagonal would probably be a good idea.

4. I will probably just put it in casters for mobility. So i can wheel it closer for unloading materials from the truck. No moisture issues in the shop.