[Graham]

To be honest I would rather hear from people who have lots of questions before we get into it, then those who wished they had asked questions and are disappointed.

1. I see why not, but not talc for me at least this year as it would make a mess inside, but I have thought if I did this outside in future years that would be quite possible, but wet sand or artificial wet grass, sounds great to me. I think blackboard paint would be too mild.
2. No foamed tyres, it may soak up the water when it runs through the river