Hey, you're the smart guy here :-) While we were arguing on the math, you went out and actually worked on the boat!
IMO 8:1 gets you all you need (especially when that adrenaline picks up in big air), but a 16:1 can be more easily moved by a weaker crew, and with very thin line for POSSIBLY some weight savings (more thin line and more blocks vs thicker line)

Chris