Some will say that nothing in this world happens by accident, but if we reject conspiracy theories - I don't see how all these events are connected unless EM works for the Chinese, and at the same time they have a special team of assassins who eliminate those who have some evidence against them.
It all sounds to me like another in a series of films from the Mission Impossible series - especially since you mention the G7 at the end - which is actually just a cover for those who actually decide everything. At the end, who can prove that JM and Popescu were killed when they both died in a very appropriate way - one in a prison cell and the other in the depths of the ocean, the truth is as they presented it, believe it or not, nothing will change.
In McAfee's case, it is clear that he committed suicide. He had previously given hints as well. Being an such an egoistic person, getting deported to the United States was something which he could not get himself adjusted to. Now the investigators will have a hard time in recovering the coins which he made during the ICO boom. However, the case of Mircea Popescu looks very suspicious. What are the chances that someone like him would venture alone in to a section of the beach which is known to be dangerous?