In the looks department, I think Johnny Depp is a bit thin, and he doesn't share any of the body characteristics of Persian descendants. I know he has a very distant African-American connection, but he doesn't seem to have any trait that the western world would describe as "ethnic." I think they should go with a person of color over a white guy with a glued on mustache.
If the original post had been 2005 I could still just about understand it, but in 2015 when the original poster wrote this, Depp was already 52!!!
I think Depp could have played Freddie 20 or 15 years ago (and if the film had been right I think he could have done a good job potentially), but 15 years ago has to have been the limit.