I have to say that I agree with Teamubr on pretty much all that he has said.
1. I wear a ball cap all the time at the parks. If I am concerned, I just take it off and hold it in my hand or sit on it. My dd had a hat with her on the one trip and her hair is long. We just pulled the hair through the adjustment strap in the back and it worked well. It did almost come off on Space mountain, but because her hair was pulled through it allowed her to quickly stop it before it got to far.
2. I think the "Green Sign" was just a unique way to easily and quickly identify Disboard members. Some were on poster boards, some were on wood, some were done other ways.... Be creative. If you keep the overall theme (the general shape/color) it will probably be more recognizable for existing members who are familiar with it, but even if you go completely opposite of what was done... That's cool tool. We love pictures here so a picture would really be expected, that way we could identify it if we see it AND so we can marvel in your ideas and steal them, err... I mean borrow them if they are really good.
3. We have done Chef Mickey's twice. First time was the actual Thanksgiving dinner. I have to say, for the money, I was NOT impressed. Not even a little. The food was marginally passable and even the Character interactions were less then stellar. They rushed through like they had somewhere else to go. While I understand that they DO have somewhere else to go (the next table), it's not only the kids that want pictures with the characters..... Even us "Big" kids do too, but you practically have to time them down to get them. Again, very frustrating for the money you pay.
The second time we went, I thought it would be a bit better. Well, it was... Just a bit. The food was probably only marginally better then it was on Thanksgiving. The character interactions were also a bit better in that they didn't quite rush out AS much, but they were still rushing to move along. It was however a bit easier to nab them for the Adult Pictures too.
You can meet Mickey and Minnie in the MK (in fact Mickey is a "Talkie" too) and the others can be found in the various parks as well.
We also did Whispering Canyon for the first time in August 2016. I loved it. DD11 wasn't a huge fan when she asked for ketchup and ended up with about 15 bottles. She doesn't know it yet but we have ADRs for our June 2017 trip at Whispering Canyon too.