For casual development, focusing on ./src is barely enough to build a DApp. You may create, rename, or delete any files or directories in this folder for your favorite structure. However, to let the mother platform could recognize your DApps, you MUST keep 2 files namely bootstrap.app.tsx and static.app.tsx.
The template is built for React + Redux development. Changing to another stack requires a deep understanding of Module Federation and Micro Frontend, which is not recommended. The stack of React + Redux is pretty easy to learn and strong for state management.