Such setup does not pass a smell test as far as "for profit" operation and will collapse if audited.If there was an easy way to convert suspended passive losses into deductible non-passive losses, we all would've been doing it by now.

Balloon" framing (1920's I believe).Radon.Plaster and lathe instead of sheet rock (pre 1950's) or plaster and wire mesh variations (50's) more solid than sheetrock but a real b*tch to repair or demo if you're remodeling.You've got Galvy plumbing but also need to look out for other kinds of outdated plumbing like clay sewer lines (pre-1930's, prone to collapsing, bellies, root intrusion), cast iron (1950's, often rusted and/or cracked by now), and PB (polybutylene, gray-colored water pipes, 1980's, prone to rapid degradation and subsequent bursting, mostly gone by now).Buried Oil Tanks-- Do you have those there?

But it won't lead the way nor should it collapse like it did in 2008. 

I had one of those back pressure sewer valves put in $500 installed.It made a BIG difference as the insurance co didn't want to include coverage as the home had a claim in the past (b4 I owned it, & the city sewer backup was not the fault of the home owner).In my area if it happens you're responsible for the temp accommodation of the tenant(s) until it's cleaned up.Since then the only blockage we had was viewed via camera & found to be a city clay sewer pipe collapse.

Yet in this world you can only control your own actions, and leave it to others to maintain their own degenerate, noxious and depraved state of affairs.In taking on this role complete with the unique privilege of executive arbitration between these tenants and the city government, one encounters a mutually synergistic mass of stupidity concentrating upon itself so far that even the neutrons have collapsed.

I have heard that there is more red tape to foreign investors due to the housing collapse . . . is that the case?

Totally get that the Cape and Islands are their own world (Actually probably 3 worlds...) but they are their own very small world that would probably at best generate a couple posts a year, so this is the only logical place to put them.If this is to many then frankly you keep the 3 eastern ones and collapse Central and Western MA into one.  

The other OP was quite convinced that there was a lot of appreciation potential in boat slip values because (a) rents have been going up although prices have collapsed and (b) there are restrictions on the supply of boat slips and it is not easy to get permits to build new ones.

When that collapses, you're stuck with a sheepish grin and a lot of unhappy people.I think we will see Zestimates "correct" for the next 6 to 12 months while they sort things out and try to keep the SEC (and investors) out of their offices in Seattle. 

He has predicted just about every asset collapsing for 30 years.