Chapter 10

1. False; you can create as many abstract (required) or virtual (optional) extension points as you need, as long as the class stays cohesive and does not break architectural principles. For example, ensure the class has a single responsibility.
2. Yes, there is no reason not to.
3. No, there is no greater limit than with any other code.
4. Yes, you can have one handler per message or multiple handlers per message. It is up to you and your requirements.
5. It helps divide responsibilities between classes by encapsulating the shared logic into one or more base classes.