Legal Question in Real Estate Law in California

Yes

Yes. A remainderman has limited rights during the lifetime of the life estate holder. These amount to whatever may be necessary to protect the remainderman's future interest, and might include an expectation that the property will be insured and maintained. These limited rights do not include any right to occupy the property, nor to dictate who may occupy the property. A life tenant may even go so far as to sell his/her rights in the property to a third person. Certainly the life tenant can evict the remainderman.

I'd approach that with caution. I agree with the central premise that a life estate is entitled to possession of the property, and the remainderman has no current right to occupy the property while the life tenant is alive. The remainderman in the basic scenario has only a future interest in the property, not a present interest.

But you mention that the remainderman is renting a room. It sounds as though the remainderman may be a tenant or lodger, and subject to those rules for eviction. So I would caution against simply telling someone to get out, as there are notice requirements for both lodgers and tenants. A consultation with a competent attorney in this field of law may be in order.

Mr. Roach is right. Just because he is a remainderman, doesn't mean he has any less tenant's or lodger's rights than anyone else. It just means he doesn't have any MORE rights.