Your comments

This would fix my #1 issue with Textastic for working on my website. Currently I need to download a file from Dropbox. Edit it. Upload to Dropbox. Upload to the server. If I forget any one of those steps the files will be out of sync.

Another issue this would solve is when I add a new file to Dropbox via computer. In Textastic I would need to go to the "World" icon, find the correct file and download it. Editing live files (in Dropbox) would remove this step.

Finally, Dropbox already has (some) version control. As such I am not worried about "losing" edits.