Update: version 1.7.0 adds support for rules import and export.

Thanks for your complete review!

I will add the sync support once Firefox adds storage sync support for WebExtensions. I'll take a look if the file import/export is possible too.

Thanks for reporting the missing options in Fennec. It is odd that Fennec won't include any button to access a WebExtension's options. I have to read more about it.

Here are links for these two issues:
https://github.com/tumpio/requestcontrol/issues/8
https://github.com/tumpio/requestcontrol/issues/9

Regards,
tumpio