I'm not a member of Scrum Team. However, I'd like to get a sense of the health of a Scrum Team. What is the best way to understand a Scrum Team's performance?

To be more specific, things I would like to know:

 - Is the team running at maximum efficiency?
 - Is the team improving over the time?
 - Is the team motivated enough?
 - Is the team meeting their commitments?
 - Is the team meeting coding standards?