I agree with you - he's a jerk!

However, you can assess the late fees and damages as against his security deposit. Additionally, he had to give you one full month's notice of when he was vacating or he is liable for the next month's rent. (for example - if he gives you notice January 2, 2009that he's leaving on February 1, 2009 - then he didn't give you one full month's notice and is also liable for February's rent too)

No, emails don't count. If the lease states in writing - it didn't state email were/are acceptable.

Total up the number of times he was late and subtract such from the security deposit.

A lease becomes month to month usually if a tenant or landlord doesn't give notice to vacate when the lease term is over. The lease term becomes as per how the tenant pays their rent - if weekly - then week to week, if monthly - then month to month, etc.

I would send him a letter (signature and return receipt requested if possible) an itemization of damages showing late fees accumalated (hopefully you can show with receipts that he was late for those months, damaged to the sprinkler system, plus anything else he damaged - then subtract that amount from the security deposit and send him the balance. If he owes you money - then send a request for the balance of monies he owes you.

This letter should be sent within 30 days after he vacated the property.