in that time of basically standing there and then doing a pan of the scenery to check the framerates, the fans in my late 2013 rMBP hit plaid speed. Is this something I'm going to have to deal with pretty much any time I open any game that uses more than basic resources?
What you describe is close to a stress test, the fans don't max out when you use a little more than basic resources.
With a game (depending on the game and the settings) you can actually start drawing so much power your laptop battery can start to slowly drain even if you have a charger plugged in! I have seen games peg the CPU at close to 100% of all 4 cores and over 95% of the GPU at the same time.
When you are creating that much heat you need to have the cooling fans on maximum especially give the wafer thin packaging Apple uses for it's laptops.
That said you can play for hours without any trouble, you just get some fan noise in the background.
Edwin