Users report that a button on a custom Lightning Web Component is not working. However, there are no other details provided. What should the developer use to ensure error messages are properly displayed?

What is the transaction limit for the number of records per DML statement?

As part of a custom development, a developer creates a Lightning Component to show how a particular opportunity progresses over time. The component must display the date stamp when any of the following fields change:
* Amount Probability, Stage, or Close Date
What is the most efficient way to Query such information?

A developer receives a LimitException: Too many query rows: 50001 error when running code.
What debugging approach using the Developer Console provides the fastest and most accurate mechanism to identify a specific component that may be returning an unexpected number of rows?

A developer built a Component to be used at the front desk for guests to self-register upon arrival at a kiosk. The developer is now asked to create a Component for the Utility Tray to alert Users whenever a guest has arrived at the front desk. What should be used?