OP, sadly I agree with other posters. There is just too much to do, and too many lines, to plan to do EVERYTHING during a party. Think about it.... if you do nothing but rides and they are mostly walk-on with bare minimum standby waits, that would probably take you several hours just to walk from one to the next & get on & ride, considering preshows, etc. The party only lasts 5 hours.
I took a Disney first-timer to a MVMCP in 2010 just for the rides because she was only in town the evening before a cruise but wanted to see the park. This was the first week of December, so not in the thick of holiday crowds or a sold-out party. We got there at 4, did nothing but rides & fireworks, and actually left around 10:30 having skipped many things she wasn't interested in. I would think that if we stayed until midnight we probably would have finished the rest of the rides & maybe squeezed in a dance party. But that's it... we would not have had time for character meets or the parade or castle show or a meal.
And now you're talking about adding all the special party events, plus multiple character meet & greets, some of which have queues approaching one hour long. Not to mention you will probably have to claim your parade spot ahead of time.
Sorry, I just don't think it can be done. You're going to have to narrow down what you want to do. Definitely arrive no later than 3:50 or so at the turnstiles, hit rides hard & heavy for a couple of hours, line up well before the party starts if you plan to meet the dwarves (like 6:20 or so), watch the 2nd parade from Frontierland where the crowds are smaller so you don't have to get there as early, don't waste party time eating (maybe grab something while you are on the curb for the parade). Good luck & have fun!
ETA: aaaaand that's what I get for not paying attention & noticing your update. You've got a better plan now. Still, arrive at 4 pm & you can do some riding before it starts as well as line up for the most in-demand characters early.
