If this is a $100K property you may go from believing you have a healthy LTV ratio to being underwater in a matter of 2-3 months.

This is a good way to get underwater real fast.This is an unwise suggestion. 

Actual cost takes into account depreciation so complete destruction of a property could leave you under water in terms of the amount paid for the loss.

Land at bottom of man made lake (literally underwater)4.

In that scenario (right now unlikely for the next few years) you may get under water if you didn’t account for it.I never found a bank that would do fix rate for more than 5 years.

Forced appreciation allows me to build equity from the beginning of the investment, so if I need to firesale for an unforeseeable reason, I will not be underwater.

Forced appreciation allows me to build equity from the beginning of the investment, so if I need to firesale for an unforeseeable reason, I will not be underwater. 

Yeah if the rent stops coming in, and they’re underwater on the property, will they just keep making the payments?

Most lenders sell their loans out.Nobody wants a loan where the asset is underwater every month.The real question is, why is a property worth over $1M only producing $4,000/mo.You should consider raising rents as this seems significantly below market.

That's about what I'll get in the stock market plus I'll be liquid (as opposed to underwater the first couple of years) and it's just push button.