Even assuming the joking banter is relatively close to reality, that wouldn't seem to be a 'fatal flaw'. With El Cheato's foreign policies bouncing off the walls, many countries will be less willing to cooperate with the US, and the general backdrop would be seen as less US international leadership. I think that would fit with the Russian mafia boss's goals well enough...
Right. The wild conspiracy theories about Trump being some sort of Manchurian candidate are off base because of precisely this. If the Russians wanted Trump, it is because Trump would make the US look bad, not to use him as a lackey. At least, unless these alleged pissing videos are real and, I doubt anyone in Russia thinks they can *control* Trump, they just know that he'll make America weak due to his sheer incompetence.