Thank you for your great questions.
I would use music page change indicators, 5, 25, throughout. Notice that the Bluegrass piece does actually have page numbers at the bottom left corner. Even if it didn't, though, Music Code should be used throughout.
The FAS49 preceding the music is simply the catalog number for the publisher. In a transcription like this I generally leave that info out.
Repeats may be used if the repeated measure does not have any bowings - if the bowings are different, of course, you may not use a measure repeat.
In the first measures of Bluegrass, I read the curved lines as a tie between the A's and a slur between the F natural and F sharp. I would transcribe both: put the tie after the A and a slur after the interval of the 3rd.
What you've done with the in-accords to show the stems and rests is perfect. I just checked measures 65 and 66 quickly; look at m. 66 - don't forget the ascending curved lines before the 3rd beat. Also, there are some duplications in the second part of the in-accord that don't need to be there. Make sure you're not repeating notes unnecessarily.
I hope that helps and answers all of your questions!
Let me know if anything is unclear or you need anything else!