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Your past legal actions, property ownership, etc. are still valid (having multiple names does not void these transactions).
It is probably in your best interest to file for a legal name change to consolidate your names into the name that you choose to use. This is a relatively simple legal procedure in California: http://www.courts.ca.gov/selfhelp-namechange.htm.
It is important to have a consistent name for legal purposes - particularly when it comes to federal documents (such as your social security account, taxes, and similar information. You will want this information to match your driver's license, and state tax returns, as well as property ownership in the state.
Again, this is not a terribly difficult or time consuming task (plan on it taking about 2-6 months for all of the mailing back and forth with DMV, SSA, and other agencies to be completed once you have the name change completed with the court).