Just got her! Question real quick.

I understand and agree with what you said as it is fact. I need to read the manual, because I tried to do a low approach, but when I pushed the throttles forward the thrust limiter kicked in and I had insufficient power to do it safely, so I was confused and thought, "that can't be right."

It sounds as if the auto-throttles kicked back on after you pushed the power forward, and subsequently tried to retard the throttles back down for its' current landing mode. In other words, the auto-throttles came on for the landing phase and TO/GA was never pressed to initiate go-around mode and thrust. FWIW, when I am doing manual landings I always disconnect the A/T system to avoid such situations, as in spur of the moments when you have to suddenly go-around I want full manual control of the aircraft to do what I want when I want. When I'm in the G/A climbing out and stabilized I will then activate A/T and A/P modes as I need them.