[2022] Some beginner questions.

Hi! I started playing this game yesterday and I'm having some questions:

1) When a team mate goes completely down but is secured by me or the other team mate in the same mission: Is there a benefit for the team (more XP)? Or is it just an act of kindness to secure the mate? ^^

2) Is my following assumption correct?
- Successfully extracting gives you a 90% XP boost
- Not extracting (MIA) gives you 0 XP, but normal 100% after rescuing the operator in the next mission
- Not rescuing the operator in the next mission reduces the MIA-operator's XP?

Thank you very much! :)