Well, using water pump and fresh water tank all the time and not relying on campground water pressure and a pressure regulator wasn't really the original topic here, and I apologize for hijacking the thread some to discuss such.
However, from reading everyone's experience with this (water pump and FW tank) approach, sounds like I may have been a bit too paranoid about water pumps wearing out, and that isn't really much of an issue. I may well just switch to using water pump, fresh water tank all the time and not worry about it.
There's definitely several advantages to this, not the least of which is like already said, you can switch off the pump whenever you leave the RV and not have to worry about a pipe bursting and causing a huge mess. Consistent water pressure is nice, too.