Hiya mate,
1 - Honestly cant remeber how much you need completely but a 250ml would be plenty i would of thought.
2 - Any of the HS33 brake pads will fit. Recomend Cousts, Heatsinks or LGM's.
3 - For hubs i just use a cloth ram it in my wheel and rubb, for a sprocket, any general bike cleaner like muck-off will do the trick, if it does have chemicals in them just make sure it dont go near your rim.
4 - Bar height is kinda personal preferance, im about 6ft ride a mod, and have a 160mm stem on a 35 degree slope, 1 spacer, and tensile high riser bars, again play around put spacers in take some out see what feel comfy.
5 - Tyres, everyone really loves try all sticky's, perhaps maybe look at the maxis creepy crawlers as they're a lil heavier so perhaps a lil stronger.
Hope that helps, any questions jus ask...