I have a FP for FEA, DS and his family have one 5 minutes after mine expires. Will they let us in together? If not, is there a place where we can wait the 5 minutes so we can all ride together?
They might let them in 5 minutes early, and they might let you in 5 minutes late. Or you could scan your band, get in line and then just wait to the side for 5 minutes until they catch up to you.
You should be able to begin a FP 5 minutes early and use it up to 15 minutes late. That has been true of all the CMs I've talked to and it is always true when I try it.
I would be careful with ANY New Attraction - the CMs there are typically a little more strict with times. I would definitely try to time it at the end of your time/beginning of theirs and tell the CMs what is going on.
I know last year some of the CM's made people wait (especially soarin, 7DMT) until their FP time. So I'm thinking of just going in at the end of my time and waiting in the line till they catch up.