All accurate. Micros have the engine offset significantly to the left and the driver's legs fit down in the chassis, beside the engine, similar to what you'd see in a go kart. Minis have the engine mounted more centered and the driver sits upright (like in a midget or sprint). Both engines are mounted transversely with the crankshaft perpendicular to the frame rails where a midget or sprint has the crank oriented parallel.

In the 80's, we called them "Mini Modifieds", "Sidewinders", and later "Modified Midgets" (i.e. National Modified Midget Association, NMMA) typically with 250cc 2-strokes and some Rotax snow mobile engines. 1200cc were "Mini Sprints". In the 90's, 250cc Modified Midgets gave way to "600cc Mini Sprints". By the late 90's-2000's, 600cc powered cars were branded as "Micro Sprints". 1200cc Mini Sprints reduced engine size to 1000cc (still called Mini Sprints) and now, they are commonly called "Lightning Sprints".