If they have overstayed the visitor period, or disallowed, send a notice to cure per local law.That is a lot of extra wear and tear on your unit, as well as any utilities you are responsible for.

It depends on exactly what the title issue is......some are simple to cure, some will be a fruitless waste of time.

Make sure you are also pulling the cancellations of default.The problem with defaults is most people are able to cure them. 

Your demands need to be in writing with reasonable time allowed to cure the problem and state that you will seek indemnification for losses arsing out of their lack of timely action.

Standard purchase contracts do provide for an automatic extension of time if seller can not provide title, for the purpose of curing any title defects.

Not sure how it is in NY but usually if you give the tenant a 14 day notice, they have the right to cure, sometime even on the day of trial and you are stuck with them.

This is a BAD sign and signals the central banks haven't been able to cure the world economies with cheap money. 

In my world, this sale just turned into unacceptable unless the re-negotiated price covers 100% of the new known costs to cure the property issues to move it back into my acceptable transaction bucket, again, based on my own fundamentals. 

If they breach, and if they cure the breach, the lease continues so, even though you say you can look for any little thing possible to try to void the lease, as long as you give the tenant notice of the breach (You have to), and the tenant cures the breach, yes, you guessed it, the lease survives and continues.

If it's a lease violation, you need to send her formal notice to cure or quit (in my state it's a 7 day notice) for the extra person plus the utility situation.