To understand RR, I am re-posting my old post here:
To answer your questions:
1. If the RR is for something specific as explained above, then you can send additional documents and explanation.
2. There is no limit on how often you case request GCMS notes. You can do it as often and as many time as you like. However, you should request your GCMS notes again after the previous ones have been released. If you request new ones before the previous ones have been released, then IRCC may just club both the requests and release the most recent GCMS notes.
3. There is nothing to worry. Just read the note carefully and if you see nothing significant, no need to stress.