Exterior storage shed

Should include:

1. Concrete pad
2. Sufficient storage space for:
   1. Four bicycles
   2. A Trotec Speedy 300 Laser Cutter
   3. Miscellaneous storage
   4. Potentially lawn equipment
3. Electricity would be nice
4. Would be sweet to have the proper tools for quick bike maintenance on the exterior possibly.
5. Shed should match decor of neighboring home.

QUESTIONS:

1. Ventilation > I feel like these types of structures have ventilation...are there regulations around this or good design rules?  
2. How thick are walls in general.  I'm thinking fascia boards, plywood, 2x4, then sheet rock.  ~4.5"?  What should I plan for that?
3. The angle of the roof, what is that typically?  In the current design, they have 19 degrees (will attempt to round up to 20 degrees.
4. What other features are missing?