No — this runs entirely in your browser; your password is never sent anywhere or logged, even to CalcLeaf.
No — it checks composition and common patterns only. Real breach-checking (like Have I Been Pwned) necessarily requires sending the password or its hash to a remote check, which this tool deliberately avoids.
Scoring factors in character variety as well as length — a long passphrase using only lowercase letters scores lower on variety even though its length is a real strength. Consider it a conservative estimate rather than a definitive verdict.