Sarah,
Here's my take on the situation. I'll try to answer your questions and number them how you have them. Or atleast, I'll give you my opinion, take it for what its worth.
1. I tend to start marketing a place shortly before the old tenants move out, depending on time of year and how much work needs to be done to get it rent ready. We only show after the old tenants have moved out. We try and respect their privacy & want to avoid them trashing the place, plus we do our final inspection to determine what needs fixed, cleaned, repaired, updated etc.
2. Ask the tenant to remove the CL ad and remind them that they have no right to solicit new tenants or act on your behalf. Tell them that you appreciate their efforts to get you a new tenant, but that is not their job & you will place an ad & look for new tenants once you have the place rent ready.
3. No. Don't accept the first tenant that comes along. Never lower your standards. What ever quality of tenant that you have decided that you will accept, stick to that. If you have to, lower your price, but not your standards.
Through out your post you are hinting at the fact that the tenants owe your the balance of the rent on the lease. I ran into a situation a few years ago when a tenant threatened to break lease & move out. She was upset that the roof got a leak after a tropical storm came through. I had the contractor's & insurance folks out before it had even quit raining, so I asked her to re-read her lease, reminded her that she owed me the balance of the lease & I would see her in court if need be. She decided to stay. If she had moved, at most, I could only really go after her for rent until I found new tenants, or the difference if I had lowered the rent. I didn't think it would really be worth my time.
Generally, when I have a tenant break lease, I just remind them that they will lose their security deposit & wish them good luck. I try my best to stay out of court as it can get expensive & some tenants will start lying like a cheap rug just to get sympathy from a judge, even though our land lord tenant act is more landlord friendly.
4. If you ask for higher rent, then the only thing that should happen is you get it. If you do pursue your old tenants in court, as has been explained to me by the lawyers, the best you can hope to get in judgement, is the lost time from the first tenants contract. If the unit, under the old lease, was $2000/month and it sits empty of 2 weeks, the best you can hope to get would be $1000.
Enter security deposit. When the lease is broken, the security deposit is forfeited. You can take the other tact, offer them cash for keys, just be careful about how to use the security deposit, each state has different rule on how it can be used.
5. See #4. Net tenant, new lease. Unless the old tenant brings you a new qualified tenant to assume the lease.
6. Lease broken, security deposit surrendered to you.
7. Not sure of the small claims court limit, varies state to state. If you call a lawyers office their secretary should be able to answer that for you. I think I hit most of your questions further up in other answers.
Yes, this is a bad time of year for vacancies, you can be creative, offer to let them leave at the end of the year with no negative consequences, ie you will not take them to court, but still hold on to the security deposit. Also, remind them that the security deposit doesn't count as the last month's rent.
Hope that answered your questions.
JW