[Porsche-O-Phile]

1. No, on grade is fine so long as you provide proper subgrade for drainage and support.

2. Slab type construction is fine, but make sure to include control joints (or Mother Nature will add them for you, probably where you dont want them).

3. WWF is fine - actual bar stock is (expensive) overkill. Make sure to support it above the substrate (don't just lie it on the substrate and pour on top of it).

4. Not necessary but don't think it would hurt anything either so long as it is moisture permeable (you don't want moisture to get trapped under the slab and freeze/thaw)

5. Slope 1/8" per foot min to edges and/or to bottom. Check your local codes just in case they require 1/4" or side collection swales, etc.

6. Anything is possible - finish, color, texture, pattern(s) up to you. Question of time/money - what do you want? I recommend standard float finish or rougher for traction. In a freezing climate you'd think broom finish might help prevent slipping but it just means snow/ice gets in the little grooves and it becomes a slick surface anyway. What do the local sidewalks have (hint-hint)

7. 4000 is fine

8. 4" typically fine.

9. Crushed stone topped by stone dust usually seems to work well. There are a number of ways to go. The important thing is keep it able to drain away any moisture.

Good luck!