We were there this year on the 5th floor in the Crest of the Wave building, and our view was PERFECT!!! I highly recommend it! It was a long hike to our room, but we quickly got used to it. We ended up preferring it as there were never alot of people in the hallways making noise

EPCOT was straight out our window, and we could see all of the higher fireworks off of our balcony. Noise was not a factor for us at all, but I would imagine you could hear a bit more on the lower floors. I don't imagine it would be a problem with the doors closed though!
Halloween was great at WDW! There was a nice party on the BW on Halloween night! We attened only for a short time; because, our daughter got one of her HUGE bloody noses. I thought it best to call it a night after that. Thankfully we had done all of the trick-or-treating by then and finished the crafts

There was a DJ there and quite a few folks

The kids were all having a blast!
MNSSHP was wonderful too!!! We are going back next year since we had so much fun this year! It might be a new annual/semi-annual tradition
What things are you asking about as far as how late they are open? The parks all close early by 5-7PM except for EPCOT which is open until 9PM. The shops on the BW I believe are open until 11PM.