[Kiai]

The intakes would make sense on a level of "extreme outer edge of the atmosphere" flight, the scramjet design capitalizes on that, the intakes close in space and the "fuel" is burned like rocket boosters. I say fuel, because I did a search for macross designs and came across the cell where Ben is hit and leaking "fuel". I don't know what it is... Radar Liquid Coolant? Hydraulic Fluid? Who knows... Oh yeah, and just because you have a nuclear reactor doesn't mean its used directly for propulsion. Power consumption on one of those things has to be unimaginable for all the electrical systems. Seperate turbine engines in each leg wouldn't be too far off, which would esplain the intakes.