My question is about how to best organize many rental properties to provide best shield towards potential law suite.From this forum, I read about multiple properties (mortgage free) under one LLC; or one LLC for each...

@Jeff Arndt there are these dust trap "curtains" you can use to isolate one or two rooms at a time.

I have a small architectural practice (an S corp) and need to isolate my REI endeavors. 

This again isolates me from smaller investors.

The new construction buildings have higher ceilings, have more isolation in the walls, and all the common elements are brand new: brick work, roof, windows, heating system, etc. 

This is the only house trashed on the block so I think it's just an isolated indecent that hopefully wont happen if I buy this property.

This was an effort to isolate the bathroom GFCI to its own circuit and reduce calls for tripped breakers-needed fan in bathroom (you did mention it wasn't even properly vented) so rather than tear out the bathroom wall they tied into the living room circuit while they were finishing that area anyway.

One is to create your own secret system including formulas and contacts....and working your system in isolation.

McAllen is relatively isolated. 

The other advantage of sub-metering is it allows you to quickly isolate and fix leaks (usually toilets) by looking at the usage and noting unusually high readings.The City of Columbus only sends a bill every 3 months, and refuses to install more than 1 meter per property, no matter how many units.