Hi I have not played Arma much although I have had it a while.
I never really made campagins as i prefered the CTI/dynamic single mission style campaigns.
Anyway I have used this toolhttp://www.armaholic.com/page.php?id=1434
it is an unPBOer but also packs the files into pbo's (which your campaign file will be)
that might help but first make sure... super double sure you have the things in the folder you need.
My memory is hurting here but for OFP i am sure things are the same as Arma.
4.a sub folder for the missions
5. put your cut scenes as seperate missions so that upon reverts players dont have to watch every cutscene again. e.g if your campaign is 3 missions long you actually have 5 or 6 missions maybe more with multiple outcomes for end missions etc...
hope this helps.