Your comments
As Dave pointed out above, you also need to add <html debug="true"> to your html document when you do that.
Instead of using the feature in Textastic, you can reference Firebug Lite directly in your html file as described at http://getfirebug.com/firebuglite#Stable:
<script type="text/javascript" src="https://getfirebug.com/firebug-lite.js"></script>
This way it will be loaded with the web page.
Textastic for Mac is now available on the Mac App Store: https://itunes.apple.com/us/app/textastic/id572491815?mt=12
We seem to have similar workflows. SourceTree is my tool of choice, too. I think SCM integration is currently out of Textastic's intended scope.
I'm using Marked, too. You can simply drag the file icon from the window title in Textastic onto the Marked icon. It works excellent.
That one is on my todo list. I'm missing it, too :)
Customer support service by UserEcho