Challenges: Perfect Finish and Flawless Clear: No Damage Stage and No Damage Boss: Questions

Can I get one or both of these on the starter stage?

Is "Flawless Clear" like the other challenges, that you get them as long as you make it to the boss without damage? Or does it include the boss fight?

The Junkyard boss seems like the easiest fight to get "Perfect Finish", especially because you can use enemies as weapons.

Thoughts?