I overlooked the questions.

1. I like Purcell's funeral sentences a lot. I also like a lot of Danish songs and psalms. In Denmark the whole romantic and early modernist poetry is set to music and always sung by choir (or crowds) - here an example of a song by the fairytale author Hans Christian Andersen
   

I also love this: a multi language song.

OK, I could probably go on forever.

2&3. Not sure but I'll tell you if I find any.