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Update 2015-04-17: The latest versions of Textastic have the Fountain syntax definition built-in. The default themes are intended for programming languages, so you can still install and use the themes from http://www.textasticapp.com/support/FountainThemes.zip to make full use of it.

A customer also requested support for custom colors for synopses, actions and dialogue. I modified his theme and added styles for it. You can download this theme here: http://www.textasticapp.com/support/Highland.tmTheme.zip

Here's a screenshot of this theme:




You can use the theme editor at https://tmtheme-editor.herokuapp.com to modify colors (the editor requires the desktop Chrome browser).
It's great to hear that it works now!
I can only guess, but maybe Unicode characters are encoded differently than in the original file when Textastic saves them?

Also, Textastic changes all line breaks to be the same when it saves a file. Since in your case the result is CRLF (2 bytes) instead of LF or CR (1 byte), this could only result in a bigger, not a smaller file though.

To be sure, you would have to run the file through a diff program.
This looks like a network problem. Is there maybe a firewall preventing FTP network traffic? Can you try to use a different Wifi network?
You can use the Recent Files list in Textastic to open recently opened external files. Different sorting of the file picker list would have to be implemented in the Working Copy file picker extension, not in Textastic.
The actual problem is that it takes a while to re-layout the file if you have auto line break enabled.

If you encounter this problem often, you might try to disable auto-line breaks in settings and set a manual line break column. Set it to a high value like 1000 to effectively disable line breaks.