Hey there! Thanks so much that’s so kind of you <3
- I can’t answer without first saying that I’m lucky I get to record great singers with great mic technique. Generally I record singers on axis and very close to the mic with them backing off as they get louder. Every layer is different though from whispering up close to off axis yelling. I’d just think about what the goal is for that layer in the mix while you’re recording so you can have the mic set up in a way that makes sense. Also don’t compress too much on the way in!
Think I may have answered your second question over here 
Capture everything as high quality as possible and minimize room noise because sometimes the best takes are the first takes. Avoid stretching where possible. Fades are a nice safety net, but your edits shouldn’t pop without them. Choose the take based on the emotion and tone not tuning or timing. Take your time editing and go in on the details manually - overall processing is useful but should never be used as a shortcut.