It just a simply "guarantee" that they will cover guest caused damage.

The city must compensate you for taking property so the seller could argue that their silence on this matter caused you no damage.At different apartment complexes, we have twice had the city ask to annex our land, both times to install a sidewalk. 

That could cause issues with a lawsuit though possibly easily remediable ones.

I wonder if Newsom even realizes how much pain he causes landlords; if the laws were fairly balanced for both tenant and landlord, most people would be happy.

It doesn't mean they CAN'T appreciate - the only thing keeping a manufactured home that is permanently affixed to owned land from appreciating, from what I can tell, is the general stigma surrounding manufactured homes caused by poor quality builds from the 1970s - 1980s and the misconception that ALL manufactured homes depreciate because of those that are not permanently attached to land.

Unless the tenants did something to cause the blockage or did not notify you when they saw the flood, they aren't liable for it. 

If you are 100% LTV and there is something that causes you to sell the property you will have to bring money to close.

Who is liable for damage caused by guests?

That's almost guaranteed to cause problems and hard feelings down the line.  

What would YOU do if your PMC used an unlicensed and/or uninsured vendor and they caused a personal injury situation with a tenant that led a tenant to sue you?