Actually, Textastic does save the last selection/cursor position and scrolls to that position when opening a file.

The textastic:// url scheme works like that:

• Open a website in Safari
• Tap on the address bar
• Replace http:// with textastic://
• Hit Return
• Textastic will open and download the file at the url

You can use this feature to view the source code of a website or download arbitrary files in Textastic.

You can already create custom templates. This is explained at https://github.com/blach/Textastic-Customization

Currently, Textastic doesn't support Box.com.

Currently it's two taps. You would need to select "Upload This File" in the action menu twice.

Textastic 4.3 introduces a change that could fix this problem. The new version is currently in review at Apple and should be available in the App Store soon. Let me know if this update fixes it for you.

You can edit those files as text files and use regular expression search.

But, it will be just handled like any other text file and not special in any way.