Most of us don’t have Boosted Boards. I might buy a used V1 soon though.
You could probably find cheaper waterproofing silicon at a hardware store. Something for bathtubs or windows.
It would probably be easy enough to mod the gears on the board to increase top speed. Also switching to Kegel wheels shouldn’t be too hard.
I’ve never heard of this? No point really. Board is powerful enough.
I’d avoid adding a 10S1P 18650 pack in parallel to the 12S1P LiFePO4 pack inside. Another LiFePO4 12S pack would be great though.