Nope hes right; when you pass step 1 and 2 your MBBS becomes an MD;
My parents are FMGs from Bangladesh who graduated with an MBBS, after they finished their step 1 they were considered to be MDs
Actually, this is incorrect.
If you get an MBBS, then that's what you have.
In order to get a residency you need to have an MD or any foreign equivalent (which is exactly what ECFMG certification is designed to address).
You do NOT get to say you have an MD if you pass the USMLE.
There was a program in New York years ago that allowed some foreign physicians to convert a foreign degree to an MD, but that program no longer exists.
As an MBBS, assuming you get licensed in the US, you can do anything an MD can do. So, there is no difference except what you have to put on your letterhead, business card, and white coat.
You do get to call yourself "doctor".
As far as the op's link, UQ is a very valid school. I have no idea what he/she means by "no science courses required to attend". The school includes 2 core years of basic science in Brisbane. You must take the MCAT to apply, and although I guess you could try taking the MCAT without taking any science courses, I doubt that will work out well for most.