-Rockit will have single rider but it will be packed as is the ride. Rockit is always a madhouse after 30 minutes have passed into HHN. Mummy/Gringotts should have one that is not very long and MIB/Transformers don't get busy but they might have one. Simpsons doesn't, it will be busier in the middle of the night.
-Everything has to come out for Rockit and go in a fluffy, fluffy bunny filled with medicine and goo. Other rides you should just be able to hide it in cargo pockets.
-Butterbeer ice cream is the best. There are three locations that sell the regular/hot/frozen versions about 5 dollars.
-The Blinky cup is like 4-6 dollars extra I think. The combined version of the drink is pretty good.
-AHS is the busiest house and TWD is probably second. Go early, get to the front of the gate before open, then go right at the start of the event, go directly to Krampus, then Halloween, then Tomb of the Ancients then Chainsaw Massacre, then Chance (minimal stopping) and you will be right next to MIB/BIll and Ted/Harry potter at the point where it starts getting busy. Or do Rockit very first thing if you want to skip any of those houses. Should be able to hit them all in 1.5 hours. Do Walking dead and Ghost town around the last hour of the event and get in line for AHS right before the park closes and DON'T worry about how long it claims the line is (should be under 35 minutes real time after park close). The only house you would miss would be exorcist if you did that plan, with about 4 hours in the middle to see shows and ride things.
My top 3 houses this year would be Horror Story, Tomb of Ancients and Ghost Town, then Halloween and TWD tied.
-Chance does meet guests in her scarezone, don't know about Autographs. B&T sometimes do at audience right just after the show.
Remember: Get out there and RIDE!