1. You can annotate with an Apple Pencil (or a regular stylus) on attached documents, or write with handwriting recognition with an Apple Pencil in the text fields.
2. This should be the same on Android with compatible pens.
3. You're entering the artists, right? I would recommend leaving out the articles if you want to sort by the artist field.
4. When viewing a song, you will see the personal lyrics if Settings > Account Sync > Personal Lyrics is on, or the shared lyrics if it's off. There's no way to switch between personal and shared lyrics on a song-by-song basis, but if you don't need personal lyrics for a song, you can just not enter them and then the shared lyrics will appear.