Yes this would be a problem when working off a server. DDE just adds a lot of traffic. But even without source control I personally prefer to work on local templates. It's just faster and nicer. Pretty much means you're free to keep build Automatically on with no issues.
It's not the end of the world to work locally and refresh design on a test database on a server. Yes it's a bit slower to get to the testing. But DDE overall should be faster. You can create a smart icon to assist with the refresh itself. That takes some of the pain away. But yeah if you're working off the server then you would need to change some things.
I'm not quite sure what you're doing with Scheduled Replication. We don't do any of that really. So you do need to be careful there. Replication can mess up Source Control.
I know Russ Maher does source control differently then what I do or what I suggest - though I'm pretty sure he develops on a local template.
Glad you liked the show at least!