What is dangerous is to drift into the hype and make emotional decisions based on the market behavior rather than what your numbers are saying.

Unfortunately not all new things are dangerous to us, so it can prevent people from doing good things.

Make sure your lease prohibits dangerous items such as swimming pools and trampolines. 

But I think there's some serious danger signs out there.

But raise the caution/danger flag for those that are - and author of this thread.

Those springs are dangerous.  

Separating out all the electric to have an additional extra meter is one expensive item; having to install a 'house meter' when you have the main part of the house rented out is another item to consider.Depends on the location - definitely allowed here and not just for old buildings (had to replace a panel last year, adding the pole required by new code, as the old one had wires tacked to the paneling, essentially, and drooped dangerously low (technically, could have let it ride, but safer to just replace).

This can be a dangerous situation since intake air for combustion can then start being pulled in via the chimney / exhaust; that also starts to hamper or even suck in exhaust gases.

If you've got documentation the tenant is creating danger for the surrounding residents, I'd give him a 72-hour (or whatever) notice to cure.

Yes, it's more dangerous and depends on your circumstances, but in all when you're 50 or so you'll look back and say you you did right thing by controlling 8 properties or so vs. 5 F/C especially in today's low rates.