(For example, if they could predictably produce 30% annual returns with low risk, many would be happy to invest.) 

Metro Detroit is more like a typical suburb area so its easier to predict and you can take a macro approach.

From an objective perspective, cash flow is decent, market appreciation is very solid and predictable, and the demand for short term rentals in this area is growing rapidlyAs mentioned above, you do have a few restrictions to take into account when purchasing in Naples, specifically, but these are easy to navigate as long as you know what to look for.

Their predictions are as good as weather forecasters...I live in Silicon Valley and folks have been predicting crashes since last 5 years , and homes go up 10-15 % a year...

I recently read a local business journal article that predicted insurance was going to go up by approximately 20%.

Having larger bathrooms and not being crammed into a small space. 5) Seeing return on investment, historical appreciation (which doesn't necessarily predict future appreciation), rental comps for LTR, MTR and STR so prospective buyers if your market area supports MTR or STR. 

If rates do the opposite of what the street is predicting, and HELOC rates were to rise, and I can still comfortably cover that higher HELOC rate, and all my other ducks are in a row, why not leverage the equity in my home if other ducks are in a row?

The second is the lack of predictability.

you don't sell it unless it's margin call.In real estate market since there's 30 margin call, everything is predictable, as long as you can pay the mortgage you are all set.Problem mostly happened due to personal issue, for example, if one is having 8000k monthly mortgage , RE price going down, and folks get lay off.but even then, in reality, in real estate market post 2008, even if market tanks, it's shortlived, the downturn post 2008 only occured for six months, very easy to mitigage as long as one doesn't over-leverage and two, having backup plan.

My thought is to keep it until about 6 months before your time limit is up.No one can accurately predict if and when we will have a recession or even what affect that might have on the housing market.