The fingerprint reader on this key is for unlocking the key to let it generate a one time password/token. Non-fingerprint key asks you for a password, then you have to touch it to prove that you are physically near the key. The fingerprint simplifies the process as it's enough to touch the key. For Enpass, I don't know since I'm not using it, but if it supports unlocking by a FIDO key then it'll work as you desire. However I doubt it. FIDO keys are designed to be a means of 2FA (second factor authentication), which strengthen the password protection. It would be odd if any software decided to use them instead of a password.

No idea, you should contact enpass and ask them that question. This product is not a fingerprint scanner. It uses your fingerprint to send a one time token,, "not password" to a service that supports hardware keys