Yes, you would still have to edit your custom templates and stuff with Webmin, but its great for generating the settings for you if you don't know what you are doing. Think of it as a example generator.
If you have the time, I think reading the man files, faqs, and posts and learning what things do and why is the best way to go. If you have to get something up and going NOW, sometimes you take some shortcuts and clean up later.
Just my opinion. Thanks for the warning on Webmin though, I didn't think about it when I posted.