> Hebrew and Arabic are written only with the consonants, far as I know, with the idea that you can fill in the vowels according to the structure.

Not sure if this is really relevant or of interest to you, but I know that some see traditional Hebrew as a phonetic alphabet that mimics sonic verbal pronunciations. A Dutch thinker of the 17th century, Van Helmont, wrote a book called "The Natural Alphabet" in which he speaks of the divine and pure nature of the language. This seems to have something to do with Kabbalah - mystical Torah teachings. But what interested me is the notion that the characters of the alphabet can be seen as a type of two-dimensional map of the phonetic sound that was/is created. As such, the language apparently looks like its verbal, audio source might look when disstilled in computer visualisations.
I can't seem to find any scientific work regarding this topic online, and as such, am not sure if this is really based on any fact or perhaps just religious fervour, but I think it a quite fascinating idea nonetheless.