3 subjects all together about replay for students and choirmembers

Good afternoon Musescorers,

I am a choir conductor and my choir members and students practise their music with the musescore app or software. I have 3 questions, all regarding replay.

1. If they work on Iphone or Ipad and they wish to practise a certain fragment a few times they HAVE to go back to the very beginning of the complete score. What they need is to be able to play a specific little piece. Any ideas?

2.
when people work on a PC they can put their cursor on the note from which they want to start the reply of a certain part of the music. However sometimes by doing that they replace a note so it becomes another note. Usually the replacement is unnoticed until the next choir rehearsal when they say: it is written in the score :)
So what we need here is to be able to fix the score for replay sothat the uders can replay; go louder or softer, slower or fasterbut be NOT able to unvoluntarily change the notes.

3. point 1 and 2 could both be solved outside of the musescore software by the possibility of making a video recording of the playing score. How to do that?

I'd appreciate your answers in my mail: marianvanloon@gmail.com

Many thanks for the help

Mari'an