The happenings at
MVMCP are in different locations, so it depends if you are hoping to see all of the shows, or if you are interested in certain things only.
You want to be near Space Mountain where the earliest show (6:15 - Twas the Night Before...) is. You would most likely want to see this showing so you can be over to the castle area for the stage show there later. Also, you can get your family photo taken at the old Alien Encounter building, which is right there too.
The fireworks are only offered at 9:15, so you would want to make sure you have a good spot early. Near the hub is probably the best idea for this (we were between Casey's and Crystal Palace and this worked well for us - also a good spot for the next show we went to).
Goofy's show is only offered 3 times, and if you want to see it, I suggest getting one person to get in line over there about 20-30 minutes before the show (I was that person after the fireworks so we could catch the 10 showing). Also, unless you want to do some dancing, go upstairs (the old Diamond Horseshoe building) and you can sit and relax (no chairs downstairs - seating on the floor, also you are going to be dancing if you are downstairs!).
As for CP - if you are going to eat a larger meal for dinner anyways, then I suggest the dinner package! Just be aware that the dinner package deal does not mean you won't have to stand in line! We had 5 dinner at Le Cellier (WONDERFUL!!!!) and headed over to watch the acrobats in China at 7:30 (hadn't been able to work into the schedule earlier) because were weren't doing the CP until 8:15. At 7:15 the line was already formed for the Dinner Package seating! In fact, when we came back to get in line, the line was in Morocco and working towards France! However, a CM did tell me that you were guaranteed a seat even if you didn't show up until 8:15!
As for the seating for CP, it is in the theatre, and as long as you aren't behind a tree or pole, you should have a good view! Some spots are probably better than others, but as long as you have a seat, you are going to be able to enjoy it