Jesse Waters & Roy N have posted some good advise.Being a So. Ca. landlord perhaps I can emphasize and fill in a couple of items.
1)When should I start showing the place?
When you get a candidate who passes your phone screening and if your rental agreement allows it, and if the current tenant is cooperating and if the current tenant has it in rent ready condition. Otherwise only after you get possession and have put it into rent ready move in condition.
1A) I'm concerned that even if the tenant says they'll move out nine months early and I find a replacement, what happens if the tenant doesn't move out so early?
To encourage him you might try an early lease termination fee of 1.5 months rent.
Since he e-mail informed you he was moving out, write him a letter confirming the conversation, the move out date and offering him the opportunity to schedule a pre-move out inspection within 2 weeks of that date.
1B) To avoid that situation, should I market and show the place only after the tenant left? Or, will that violate the reasonable attempt principle?
Since he has not yet moved out, you have no damages to mitigate hence you are under no obligation to make a reasonable attempt at anything.
2)Tenant has already started to show the place. How do I respond?
Thank him for his efforts and remind him that any applicants have to pass your phone screening, fill out an application, pay an application fee, be credit checked, criminal background checked, be bad check checked, have documented verified income, be employment checked and meet all your rental criteria.Have the tenant tell the applicants to phone you to start the process.
3)Do I need to accept the first non-bankrupt, non-felon applicant?
Nope, you can accept an applicant who best qualifies, even if this means the place stays vacant.
4) What happens if I ask for higher rent from new tenant?
You ask for what you consider market rate rent.Don’t worry about any argument of unreasonable rent.Tenants already acknowledged his current rent is unreasonable.
5) If I get higher rent, does tenant still have to pay for lost rent?
Assuming you sue for a money judgment and not just possession, the judge will probably grant you a maximum of 1 month rent.
Is there a sneaky reason why the tenant is advertising it for hundreds more each month? Sure, he wants you to be eager to accept someone willing to pay more rent than you are now getting.
6) For lost rent, do you take it from Security Deposit?
If he moves out, doesn’t pay the rent and you get a judgment, that’s what you can deduct from the security deposit as well as repair costs to return the unit to the condition it was when he rented it.
7) What's upper limit for lost rent from Small Claims Court? $7500
How many months would the court give me for lost rent?
Probably a maximum of 1 month.
Don’t over think this, its not rocket science