Pio Pico is not a very good place to stay if your concern is access to the sites around San Diego. It's what I'd call a tough commute location. Nearly all your miles to get somewhere interesting is in traffic.
Campo Road / route 94 is two lane for over 10 miles up to where it becomes freeway. And it's a pretty heavily traveled road. Jamul along the way is a bedroom community with everybody heading into and out of the city morning and night. And 94 also has lots of traffic commuting between east county San Diego and Tecate, Baja. And even the freeway part of 94 is heavily used for commuting traffic into and out of the city.
Taking Otay Lakes Road over to I-805 is mostly through a heavily built up area with lots of cross streets and traffic lights.
Perhaps if you got a late start every morning and went back to camp late in the evening it would be manageable.