Apparently, the freezing during pit stops issue that I've been having only happens at Texas (or at certain tracks). I've been able to run complete 15% races at Charlotte, Phoenix, Vegas, and Darlington without it happening, but it happens every single time at Texas, without fail.
Also, it definitely seems to be easier for me to pass the totally oblivious, often 2-wide AI (on Veteran difficulty, at least) on the outside at the 1.5 mile tracks than on the inside. If I go high once the tires start to wear after a few laps, I fly right past them. If I go low, there's at least a 50/50 chance that I get hooked in the right rear.
I'm officially invested at this point, boys. No more Heat. It's NASCAR 21 or bust.