What is the best practice to initialize a Visualforce page in a test class?

An Apex Trigger creates a Contract record every time an Opportunity record is marked as Closed and Won.
This trigger is working great, except (due to a recent acquisition) historical Opportunity records need to be loaded into the Salesforce instance. When a test batch of records are loaded, the Apex Trigger creates Contract records. A developer is tasked with preventing Contract records from being created when mass loading the Opportunities, but the daily users still need to have the Contract records created. What is the most extendable way to update the Apex Trigger to accomplish this?

A company has a web page that needs to get Account record information, given its Salesforce record ID, from JavaScript on the page and then display it.
Which method of integration is optimal?

For compliance purposes, a company is required to track long-term product usage in their org. The information that they need to log will be collected from more than one object and. over time, they predict they will have hundreds of millions of records.
What should a developer use to implement this?

A company needs to automatically delete sensitive information after seven years. This could delete almost a million records every day.
How can this be achieved?