How do I add a subtitle that is right/left aligned? And how do I add lyrics at the end of the song, i.e. not between the staffs but after the entire score?
NWC1.75 doesn't have a "subtitle" feature, as such. But you can do what you want to do this way: Place the item(s) as text. You can align left/right with respect to the staff. Then, give the text a staff position that is very high (or low) relative to the staff.