Wow, your equipment and layout looks almost exactly like mine (spooky!), including the arrows on the pipes. Riverbend-Sandler built our pool at the beginning of 2007 (and did a pretty good job), so I guess they built yours as well.
My Nature2 has been sans cartridge for 2 years now (1 ppm Cl, as recommended by N2, just didn't work). Is the push-pull valve a replacement? I have a Jandy backwash valve
Anyway, I understand about the time constraints, but once you've switched over to BBB and "gotten to know your pool", the time needed to keep it sparkling really is minimal. Borates help tremendously in making the water crystal clear and very predictable.