I didn't miss the sex-ed classes...but I remember all the parents had to sign a form allowing their kids to attend this class. But there were some kids in the hall whose parents wouldn't sign and they didn't go to class. Of course, most of those kids got hands-on training at an early age, much to the chagrin of their parents and elders...
I remember pep rallies being off-limits for us as well...except I went anyway. I liked going...and going to the football and basketball games as well.
All the JW kids met in an empty office during the rallies and any other assembly that was about school politics or religious in nature. The one and only time that I stayed in the office with the other JW kids, the assistant principle locked us in the room and went off to the program. I wondered then, what would happen if there was a fire or emergency. After that I always went to the assemblies and programs, even if it was something I wasn't supposed to go to.
The one time I did subject myself to being isolated with the other kids, the assistant principle didn't believe I was a JW. He had been in on too many of my disciplinary actions in the past. He thought I was just trying to get out of going to the program on voting for a class president. The other kids had to vouch for me, that I was in fact a JW. Part of me felt bad, for bringing reproach on "jehovah" but part of me was glad that my double life was working and most people at school didn't know I was a JW.