Yes you can copy them, but there does have to be availability for that to work. Most of the rides will probably be no problem to do this. However, expect there to be problems if you want A&E or 7DMT.
Some things that could happen-
1) They could copy perfectly.
2) You may be able to copy perfectly to some members of the party and not others. I would use this strategy if you want that 7DMT or A&E and can't get it when trying to copy to all memebers. If you try to copy to just one person, it may show availablity whereas if you try to copy to the entire party it may not. I would try for the entire party first and then break it down to individual members if that particular FP is that important to you.
3) It may copy, but may not give then entire group the same time. This happened to me when I was booking A&E. We booked 1/2 of our group and then copied to the other 1/2. One group had a return time that was 12-1 and the other group 12:05-1:05. So definitely workable.
4) There may not be available times. If there are no available times for a particular attraction, it will put an alternate attraction in its place. For instance, if I have SM, 7DMT, and BTMRR and 7DMT has no availability, when I try to copy them it will still give me SM and BTMRR at the same times, but will show an alternate attraction such as HM in place of 7DMT.