I can't answer all your questions but here's what I do know:
Something else to keep in mind - we've found 'real' food offerings to be hard to find during the party. There are only a few counter service options available. So either expect to eat desserts and candy or plan for dinner before the party starts.
I've watched the fireworks from New Fantasyland, behind the castle. It was amazing. You could see them very well and hear all the music. I've also watched from the benches beside Aladdin's Magic Carpet in Adventureland. The music wasn't as loud but the fireworks themselves were still great to see.1)We may be interested in the fireworks show, but understand the hub will be gridlocked. We want to take advantage of the low ride lines at that time, but there may be chance we’d like to stop what we are doing for 20 minutes and watch the fireworks from afar (unless you say it’s easy getting in and out of the hub at that time). Are there any recommended spots not in the hub where we’d at least see the fireworks? We’d miss the pre-show and any projections on the castle, but would we still hear any music or sound?
Yes! In fact they'll be handing out candy as you exit the park. Last year it was Dove dark chocolate pieces. I stopped by every cast member.2)If I get the urge for some last minute candy, do they continue to hand it out at or near midnight?
No. It always starts in Frontier and ends at Main St. If you're quick you can watch from Frontier, cut through Adventureland and make it to Main Street (by the firehouse) to watch it twice.4)Does the parade switch directions for the second show (ie Frontier to Main St, then back?). Basically, where is the start of the second parade?
Something else to keep in mind - we've found 'real' food offerings to be hard to find during the party. There are only a few counter service options available. So either expect to eat desserts and candy or plan for dinner before the party starts.