Cypher has answered the questions so just adding my own experience on the painting side etc.
1) It's silent basically - has ball bearings.
2) Won't make any difference but see Cypher's point above. I have never painted the stand on mine - just the actual wheel,inside and out.
3) Ditto above.
4) Although it dries very quickly I've had issues with it still being a bit sticky after two coats without a longer drying time after the first coat. So I tend to do the first coat one day, leave it till the next day and then do the second coat - it's then ready to use later that day but again I tend to give it a good 12 hours to be fully dry/set.
5) Cypher answered that - the cork surface is still plenty grippy enough even though it is a different texture after being painted.
Colours. If you really want it white ....I have only used the clear one and the garden green one. I like the clear one for keeping the pale wood colour. The green one ends up looking quite glossy - nice if you like green
