Wow, I almost killed my BlackBerry trying to read all 46 pages of this thread, but I did it!
Let me add one thing that has come up recently (though not at Disney, but I'm sure it will this summer!):
If you hear a child make a cough (a single one, it may repeat, but we're talking a throat clearing cough, not a hacking up a lung cough), don't turn around and give him/her a dirty look. My DS has Tourette Syndrome and one of his tics is a cough. A real simple, throat clearing cough. He's had it for more than 2 years now, but only in the past 3 months has he started to get mean/nasty looks for it.
The BF comments were all interesting. I don't wish to have my DS (6 yo) discussing "****ies" the rest of the day, but honestly, we're at WDW, if he can't find something to distract him after that, Disney isn't doing something right!
Ditto on blood sugar and insulin injections - DH will use all the discretion he can, but the heat can get to him and there are times we must check right then. He doesn't want anyone to notice what he's doing, so please let him be.
Oh, and I have to admit, I have been one of those people to take a pic of someone else's kid with a character. Here's why (and please know, I delete the pic, I don't want it): sometimes I can tell the lighting might be funny for my camera. Maybe it's shaded or we're inside with flourescent lighting and I'm not sure what setting will work on my camera the best. I test out a shot or two while the people in front of me are taking pics. This way I know what works and I can get the shot right without major shadows and you're not waiting on me to get my camera right. Sorry, I think in the past I've explained to the person ahead of me what I was doing, but I'm sure at times I forgot to do this.
So, DO pick the couple of things important to each person, do those and have fun!
And, if you have 9pm ADR's with kids (as we do this trip), consider that a dessert/2nd dinner for the kids and feed them earlier in the evening! We've done this before and it works great.
Oh, and if you saw us playing with our camera at San Angel Inn for dinner 2 years ago, we waiting 50 minutes for our food. This kept our kids entertained and was some of the best pics we had from the trip!