"How much time do you spend in line waiting to have these made?"
The longest we waited was 10 minutes.
" I especially want our formal night with Mickey and Minnie."
They come out really cute!
" About how many do you usually have taken on the 4 day."
I think my family had opportunity to take 2-3 posed, backdropped (all different: life ring, park??, ocean, etc) portraits each night. this doesn't count all the character pictures that their official photographers will snap for you. You can also take your own pictures of the characters.
" Also is this different from the formal picture taking sessions they mention in the navigators?"
I believe these were the ones mentioned in the PN.
We didn't purchase any of the posed formal pictures. We did purchase the pictures of my family all dressed up with the characters. I was tempted but made DH toss the ones I wasn't 'in love' with quickly into the "not going to buy" bin.
HTH, if you have any other questions, just ask.