I'm glad that changing the language fixed that problem for you. :)
However, The 2014 theme (which I wanted to use) has a problem is that the aligment of the Primary menu is incorrect.
Can you give me more details about what's wrong with the menu alignment? I just checked on a test blog in Arabic using the Twenty Fourteen theme and didn't notice any problems, but I might not be seeing the problem that you had.
However, A have a question, Are themes like Expound and Oxygen have the capability to change "Read more -->".
If you're using the "More" tag, you can customize what it says by creating a custom read more message.
If you see something in the theme that isn't translated, you can also help fix that by contributing to the theme's translation. We have more about how to get involved in translating WordPress.com here: Translation FAQ
Please let me know if you have any questions about that. :)