What does BUMP mean?
These are all very good questions.
I await the answers along with you.
For your 1st question, do you mean to ask whether the chants in the Mass were altered in the permitted Tridentine Mass, or are you asking about the NO? I don't think that the chants in the Tridentine were altered. I've got an altar book from France that is close to 100 years old and the chants look the same, except that there were more varied responses for throughout the year. We still have those variations in the Tridentine, but I don't think all the priests use them. I don't know if it was like this also 100 years ago.