Pleasanton, Dublin and San Ramon are all excellent choices. These are very family orientated cities and have so much going on for kids. The schools are very good. I personally live in Pleasanton and moved here because of the schools. I think moving to Pleasanton was a very good decision and my family has been very happy here.
I sell homes in all three cities and my buyers have been very pleased with the homes they bought and the friends they have made there.
As far as property values going down, none of us can say what may happen in the future. Right now we can say that there are multiple offers way over asking price in Pleasanton, San Ramon and Dublin. You should look at the benefits that come with home ownership, quality of life, and not worry about thing that are beyond your control in the future.
Over the last 50 years with up markets and down markets, high interest rates and low interest rates we have averaged almost 7.4% appreciation per year. If everything is average, and in the short term it never is, but if it could be and the future is like the past, then in 10 years your home will be worth about 74% more than it is today... if you don't refi then your loan balance in 10 yrs will be down by about 20% ... and if all that happened and you sold at the end of 10yrs you would have in your pocket approximately what you paid for your house originally.
So, go find a house you love in any of the areas you want to be in, stay a long time and enjoy your life and family... economically things will work out okay.
If you want to discuss things further feel free to contact me or discuss it in greater depth with your existing agent.
When buying a home, in my opinion, you should be buying based on the current ability of the home to meet your needs effectively, not long-term appreciation. Since we never know how the future will perform, I'd focus on immediate issues: Which neighborhood do YOU like best? Which school is the best fit for you child? Which home will need the least amount of ongoing maintenance? And so on.