Yes, the landlord can in most cases show your apartment to prospective tenants towards the end of a lease so as to find new tenants for the next term. In some cases, where the lease expressly stipulates this, the landlord is limited in this respect and may only be allowed to show the apartment during the last 30 days, or only during certain hours that are convenient for the current tenant, and only upon coordination with the current tenant. It all depends on the language of the lease. But if the lease is silent on the matter, it would be typical - and reasonable - for the landlord to have the ability to start showing the apt. to others towards the end of the lease (say, last 60 days). Obviously, if you sign the extension for a second year, the point becomes moot and landlord will no longer need to show the apartment. You can not simply go to a month-to-month arrangement unless the landlord agrees in writing (or via his/her behavior, i.e., simply not objecting to your staying on and collecting your rent on a month-to-month basis).
The property is in CA.
yes your landlord can.
noc from landlord no objection for reopen gas meter
No. That's not the landlord's fault.
Yes. A landlord can live wherever he or she wants to.
A landlord can APPLY for a restraining order on a tenant
Yes they can, unless your state specifically prohibits this.
Yes! Your landlord can require anything he wants in the lease.
Yes.
Yes.
21 calendar days from the day that you vacate the premises.
Yes the landlord can be sued for breaking the lease.