1. Can you give me an example of what you want? In python, you can either use "#" before each line to comment out multiple lines, or you can use triple-quotes to use a multi-line string as a comment. AFAIK there are no real block comments in Python.

2. If the encoding isn't detected properly, please use File -> Reopen with Encoding before you change anything in the file. 

I couldn't find a solution. It seems like the .as file extension is registered in the system as "AppleSingle Archive". In iCloud Drive on OS X it has a file icon that is similar to a .zip file.

So it looks like iCloud Drive treats it as a file archive and doesn't allow it to be opened as a text file.

You can enable this feature in system preferences. See http://www.textasticapp.com/mac/manual/lessons/Why_aren_t_documents_and_windows_restored_when_I_re-open_Textastic.html

I see. I'll consider it.

When editing a file in Textastic on iPhone, only a transparent status bar is shown. This allows you to scroll to the top with one tap on the status bar and to the bottom of the file with a second tap.

Is this status bar already too much?

This seems to be a global setting that cannot be disabled per app. Also, some users may want to have it, for example if editing comments or Markdown documentation.