If it's just a conversation, it doesn't hold any merits, and her lease states she can stay there until the end.    

Have there been previous complaints (whether or not you felt they had merit).. there seems to be quite some ways between a missing rent and a discrimination complaint.

I think both arguments have their own merits.

Since you have no way of knowing what the verdict was on the crack, you might be getting yourself into legal trouble by making claims that may or may not have merit.

But again, each property should be looked at on it's own merits.  

Some claim using an LLC for each individual property is the only way to go, others claim there is little merit to this and an umbrella insurance policy is how it's done (but only up to so many properties?)

Each property assessed on it's own merit.

What better opportunity is there in this life than to start a company and rely on your own merits?

It's actually the first option given in the Purchase agreement that the MN Bar puts out publicly.Your last point definitely has merit, probably a greater risk of having to give back the deposit.  

-month-to-month leases with pre-approved sub-leases over the summeror you can target the quiet/too busy students (law, medical, international merit awards, doctorates)