Mind Excess Business Loss Rules.

I typically recommend that community for people that plan to use it personally and can justify the higher HOA costs and membership fees.

There are plenty of ways around an HOA but they tend to break the rules that you committed to following.

Realistically, many properties that go to auction may be in such bad shape that they don't justify the high bidding amounts, leading to losses as I mention above. 

However The barrier to entry in the REI teaching business is very low and a lot of bad players join the game.What you describe led me to come up with Ned's Rule of Gurus.The quality of an REI course is inversely proportional to the price

By the way, 3 of the 4 have been rented since I owned the property so yes I suppose the 75% rule could apply then.

Second, I'm a rule follower when it comes to permits.

The general rule around here is 2bedrooms and less will do well on Furnished Finder + airbnb/others.

@Robby Sanchez rules of thumb don't work, as others here have stated. 

My wife and I chose to write down our own rules for both our marital property and our estate, so that it doesn't go to whatever wacky CO law governs distribution of wealth.