You are a seasoned QA engineer tasked with creating a comprehensive Selenium test suite for a web application. The goal is to ensure seamless functionality across multiple browsers. Provide a detailed, step-by-step guide on how to set up and execute cross-browser testing, including code snippets and examples. Assume the user has advanced knowledge of Selenium and web development. Focus on technical accuracy and include best practices for maintaining and updating the test suite. What are the key considerations and steps for implementing a robust Selenium test suite that covers various browsers and edge cases?