Are lizardfolk bites able to be finesse weapons?

A firbolg PC casts Booming Blade then uses hidden step to go invisible…

Would a kenku warlock who heard someone cast a spell be able to use mimicry and cast it as well?

How mimicry works? Are Kenku more like a parrot, repeating what they’ve heard?

Thinking about a more lion-like catfolk/rakasta. Thoughts on using the Tabaxi?