Legal Question in Wills and Trusts in California

It depends on a number of fact specific details that can only be provided by reviewing the Trust and related papers. How was the house inherited? Through the trust? Through Probate? Was the home a specific gift? Were the monetary gifts specific bequests or residual gifts? The son should consult with an attorney that will be able to review the specific documents.

Yes, but it may be not if, for example, the son obtained the property by Joint Tenancy.

As Mr. Feldman said, it would depend on a number of factors. Probably the most important is whether the house was a specific gift to the son, or part of the residue of the estate. If the latter, it would most likely have to be sold unless the residual beneficiary can come up with the money for the specific bequests (possibly by re-financing if he doesn't have the cash.)