In the end, it sounds like you're going to have to balance between where you want to be living and the best place for cycling. Most of us don't really have the ability to do everyday long distance riding. Work intrudes, life intrudes. Some lucky ones do have that ability.
If you want a place to live that will compare to living in SF, you need to live in SF. If you want a place to compare to the long distance riding in hills from your front door that you can get living in Livermore, well, you're going to have to live in someplace like Livermore. There are places on the peninsula that could arguably compare to Livermore in terms of long distance riding (for variety of hilly long routes, I think Livermore is the best), but none of them would compare to living in SF. Mill Valley? If you need urban, that sure ain't it.
I've got friends who live in Berkeley/Kensington who like doing a lot of long distance riding, but the weekend warrior type. Even then, a lot of the time, they are driving or BARTing on the weekend to other places, because variety is the spice of life, and they want more than what they can do out of their front doors in Berkeley/Kensington.
If Walnut Creek isn't going to fulfill you, if Berkeley isn't going to compare to SF, then you've got to live in a place that isn't going to fulfill you as far as everyday rides out your door. Or, as sedated said, you can have anything, but you can't have everything.