I had a student midwife follow me through my pregnancy, but different things leading up to the birth meant i didn't invite her to the actual birth. you have to be comfortable, and sometimes it's not until the time that you will know whether you want her there or not. my student was absolutely fine with my decision and visited after the birth a few times.

you can refuse to give consent for an episiotomy. sometimes tearing is better to heal than a cut anyway. hopefully you won't have either!