1: 18
2: Dungeons and Dragons. Also for Magic: the Gathering number counters
3: 15 (two sets of seven and one random that got stuck with one set somewhere)
4: I have 2d4, 3d6, 2d8, 2d10, 2d12, and 2d%
5: No
6: I have the set boxes I bought them in and keep them in those
7: Yes
8: Don't...