From a development perspective, you can do everything using content packages and their XML files. Personally, I think you'll find that there are some tasks (workflow model editing comes to mind) where editing through the web interface (not CRXDE Lite in this case) is more efficient, but it is ultimately all content and it doesn't matter how you edit it (as long as you edit it correctly, that is
).
There's a separate use case for CRXDE Lite related to troubleshooting and as troubleshooting is a key part of development, I think you'll end up using CRXDE Lite a lot during development. But if you don't want to use it, you don't have to.