Another blockage between FMGs in your situation is a psychological one altap. FMGs trained outside the US are trained to be what I will call the "top gun." They are psychologically taught in an environment where they are expected to be ultimately responsible for their patients, without any so-called lifelines. Although, when they don't place into residency(for whatever reason), this training is incomplete. You are taught to be the final word, although you are taught so partially (without a mechanism like a residency, such skills are incomplete for all purposes of American physician practice). Not to say that mid-levels don't have the last say on their particular patients, they can and do, but they have an upper ceiling; and it is inevitable that they will have to consult on the more complex patients with the physician overseeing their practice. FMGs working as midlevels would be less likely to consult with their Supervising Physician (after all, that's not the mentality they are trained with), even when they probably should. I could see that being a big reason as to why the several FMG mid-level projects have failed in the past.
Mid-levels are taught to work in a collaborative practice (atleast PAs are). Their curriculum thus emphasizes certain concepts of MD training and foregoes certain aspects of MD training. This psychology of being taught incompletely to be the top gun, but legally obliged to be the co-pilot, in practice can have even more serious ramifications then the ones you stated above.