The missfire is damn near gone! Only shows up for a few miles or so on a restart, but other than that the car can putt along in 5th gear at 30mph all day long, and get up to freeway speeds from there with no issue. I'd have to say the heavy-load issue is just about gone. Fuel economy reflected it, as the car finally met the EPA numbers, at 41.38 mpg! The only driving change is short shifting and skip shifting where ever possible since the car can now actually do so!
Also, got tired of the LOOK AT ME ECONOMY CAR wheels, and painted them up a little. Still pondering how to treat the center caps, silver or black.