We were at the MK last year on a taping day. They had a huge line for the dressed "people" in the audience for the taping, and they did look cute. They were, of course, let in before us. It was crowded around the hub, and you couldn't get to the taping area in front of the castle, as it's all set up for their tv special.
That being said, we did not notice any problems with being there while they were taping the Christmas Special/parade.
The amount of parties at MK were a pain , though. One evening we went there, forgetting about another party night, and a huge amount of party people were let into the MK at 4pm. We could not get onto any rides we wanted without a huge wait, and it was really crowded. We fought our way out of the park, and didn't try to do that again on party night. This won't be a popular opinion, so don't flame me

I think that on party nights, the party should start when it is stated, 7PM, and no early entry at 4pm. Those of us who pay for a day at MK get short changed when everyone is let in early.
Just my thoughts, from the other point of view, so no upset party people too. I know you paid for the party and it is allowed to enter at 4pm , not your fault, but I just wish Disney would stick to the stated official party times of 7pm until? Just my 2 cents. Peace