Seller can substantiate that he paid the contractor far in excess of the work done, but I want to be preemptive on this if I can, despite the fact we can show the invalidity of any mechanic's lien from this GC were it to be filed.

The answer varies greatly depending on the arrangement of your deal with the owner/landlord but in general you need renters insurance to cover your contents (since you are renter presumably) and then excess liability coverage for your short term rental activities.

Raw land is often going to be someone who had excess capital to acquire the land and then at some point determined the taxes were worth more than the resale potential.

I think it's the best way for people to be buying in this newly flat market.

You should only consider switching when your current software has a significant flaw or lacks features that force you to spend excessive time on workarounds.

Damage, excessive noise and $100 per head over max occupancy.

Think about other ways to invest, like looking at cheaper areas nearby or buying single houses or flats.

After determining and correcting the source of the excess moisture paint using a coat of Killz in that room as a primer. 

It doesn't have to be 100% but even 20,30,50% can give you excess cash to continue investing. 

For instance, is it common to state to pay a flat fee of only up to $x amount in the event the seller does not cover the cost?