On the rare occasion that pairing is unsuccessful, here are some steps you can take:
Yes. You could monitor activities of your lock via the Access logs. Go to Lock Info > Activity log (Tap on the at the top right hand corner of the page)
Activities will be updated in real time when guests uses a Bluetooth key for access. Owners will immediately receive notifications whenever a Bluetooth Key is used. Pin-code entries, however, will only be updated when master uses the Bluetooth Key on the lock.