I dont know about filing being a symbolic gesture. Seems to me to be more of a legal gesture.
California has a 6 month wait for a divorce judgment to be final. However, if both of you agree, you can prepare a marital settlement agreement and file with the court.
I think it wise when you have considerable assets or kids involved to get someone (ie a mediation lawyer) to help fill out the details of all the divorce documents - parenting plan, division of assets/retirement, spousal support, child support, life insurance, kids college plans, health insurance, etc...
