Appointments + plugin manual payment or choosing to be paid

Hello I have a couple of questions:

We want to offer this to a car rental

1. Can the client select the times

2. Can the client not pay but we can mark it paid later on when received cash payment

3. Can the transactions such as paid or not paid transactions be exported to show how much is owed?

4. Can a Client register to be in the system so they don’t have to re enter their information?