Legal Question in Real Estate Law in California

Sure, you just can't represent them in negotiating or conducting the transaction.

If it is your own space, yes. Otherwise, although there is indeed an exception for bona fide "finders," I think what you are proposing to do is over the line if you are expecting to be paid for your services by the lessor, the lessee, or some other third party. As I read section 10131 of the Business and Professions Code, anyone who "solicits for prospective tenants" needs a license if it is done for compensation or the expectation of compensation.