Immediately after launch.

Crawl audits, redirect validation, sitemap submission, and ranking monitoring.

Monitoring traffic, orders, payments, and performance.

Generally no, unless absolutely necessary.

It reduces impact on sales and customers.

Migrating newly created orders and customers before launch.

Through careful planning and final data synchronization.

Verification that all systems function correctly before going live.

Through issue logs and project management systems.

Yes, test transactions should be completed.