I'm pretty sure it's Nasser...
He's born in Germany, studied there too and played soccer / still admires it to this day, as you can read on the bb.com interviews.
He's refering to Milos Sarcev as Mishko, a nickname for Milos used only by people of yugoslavian descent, Nasser is half bosnian, furthermore he seems to be in a constant dispute with Milos, he also knows many stories about him, so he must have known him for years, not sure if this is true for dennis james...
From the interviews on bb.com it's also evident that he visits getbig.com quite often, he also complained about the bad treatment of team nasser on this board...
Those informations he's giving about cycles, diureticas etc. and the vast amount of informations he remembers about other bodybuillders leads me to the conclusion that he has a photographic memory, which may not be surprising as his father worked as an engineer for mercedes benz... most of the professors I have in my engineering classes have a very good memory (they may not be very imaginative, but they can remember things and formulas it's almost scary) and they all have VERY slanted foreheads... that's a physical indicator for a photographic memory, nassers forehead has a 45 degree angle, which he inherited from his father... here's a picture of his father (check out the angled forehead):
Once he said that his really strong side is politics... nasser studied political sciences in augsburg...
His main goal on this site is to spread the truth about bodybuilding... nasser just published a book about bodybuilding, the book is supposed to inform the readers about the true conditions of bodybuilding, the stacks pros are using etc.
Regarding his writing style and his allegedly bad knowledge of the english language...
Kurt Tucholsky: "Der Vorteil der Klugheit besteht darin, sich dumm stellen zu können. Das Gegenteil ist schon schwieriger."
"The advance of intelligence lies in the fact that you can play the fool. The opposite is a bit more difficile."
But that's just my take on this gh15 guy...