Jib and Main sheeting

I bought a used scot and am thinking through the rigging and getting new sheets.

Three questions:
1. Joe Sampson's rigging (at the unofficial scot site) of the vang seems the simplest and most logical approach. You can access it from the rail and the rigging is simple. Would any of you agree? And I gather a 240 is class legal but is a 360 waco class legal for the vang?

2. Why do sailors use quarter inch jib sheets? We've begun learning with the sheets already on the used Scot, which had been a regatta winner, which were half inch polyester braid for both jib and mainsheets. We like them. No gloves necessary. Why put thin sheets on and then require gloves and 2:1 purchase to manage? Why not go larger diameter, a little more friction, no gloves, easier to handle in heavy air that way. To our as yet untrained sailing eyes the only disadvantage seems to be in very light air, but then there are the other tradeoffs. Are we missing some logic?

3. And finally, how is it a big advantage to have the jib blocks on the seats? I know winners do it, and Kelly Gough says it makes it easier to release the jib sheet from its cleat. Perhaps, but it makes it more difficult to re-cleat from the rail, does it not? And when the boat is heeling a bit when racing, how it is a big deal to uncleat the jib sheet from the block on the side deck anyway? What are we missing, or is it more simply convention?

Thoughts anyone????