Questions about Arabic
You should definitely learn the script. It's not that hard to learn, though it does look dreadful. Being able to read at a decent pace is another matter entirely.
Except if you have access to people from a specific region, or are only interested in a particular country, it is wiser to start with MSA.
Yes i think she have to learn the script. She can approach a Arabic translator if she could.
As for the script, it would be best just to learn it. It's not hard. I found a book years ago that introduced the script a few letters at a time and used those to build a basic vocabulary and rudimentary sentences. The focus was definitely on the script, though. That seemed to work well for me. I don't remember the title, but if you look up "Arabic script" on Amazon you'll find lots to choose from.
Adding a Latin transliteration is not something Lingq could implement any time soon, I'm sure, and it would be distracting and of limited use in my opinion.
Full disclosure: I really don't know Arabic. I worked through the the aforementioned book, and I took once-a-week evening classes in Arabic for two semesters. That gives me some experience to share with learning the script and some knowledge of how it is used, but it's been a while, and I've forgotten most grammar and vocabulary. Still it's nice when I see Arabic or Farsi to be able to see something more than scribbles.
I can only answer some of your questions. I am native Arabic and all literate Arabs learn MSA in school, and it is the language of the news, the newspaper, magazines and almost all articles and books. So if you speak MSA you will be understood anywhere. Once you know MSA then you can pick up the dialects easily from TV shows and songs and with some help because the structure is very similar (grammer, gender, articles, 90% of the words, etc).
Arabic is an ancient language ( it is thought that it emerged in the way it is around 1900 years ago), so the grammar and the number of vocabulary is large. But it is the latin of the Muslim world. Meaning it influenced many languages like Farsi, Turkish, Urdu, Pashtoni, Hindi, Somali, Swahili, and even Malay.
wish you all the good luck