I am not an arabic scholar, but I did have to take arabic from kindergarden though my final years of school, even Yeshiva.
The Arabic for “allah” is not symetrical. In the clear photos, this just appears to be a curved line.
There might be some sort of symbolic script I don’t know about, but it just looks like a design to me.
The ring is a composite. It is made up of jewelry from different women (or men?) Obama knew as an adolescent, before his arranged marriage to Michelle.