I told her that I didn't want to back out of the sale and she stated that the attorneys and courts will have to figure it out because were not loosing 12,000 on this sale. 

And you can sell one piece of property and use the proceeds to buy (either as cash or down payment) several new pieces.

If he doesn't cure by Oct 15, but does pay the Oct rent, can I proceed with eviction based on non payment of late fees?

NOTE:  The property was in demo court when I closed. 

You may find yourself sneaking around and then arguments about when you can come on the property and courts and just a whole mess over a cigarette butt.

The first GAREIA meet up I went to had one guy talking about how he spent 3 weeks trying to get out of $210 for court fees.

I would use the proceeds towards another flip.  

He will/should ask you to share your short- and long-term goals with him so he can help you construct a plan that will enable you to achieve your short-term goals and reap benefits from those goals that will provide you with the proceeds and resources needed to pursue and achieve your long-term goals.

The son said that the father took out a reverse mortgage and that after the father died, the son went to court and the judge said that the mortgage company could not take the house.

This is where the courts hold the rent until repairs are done.