And the gross rental income that you would decrease by 75% is held against the debt loan for that property, meaning taxes, insurance, HOA (if applicable) and the mortgage payment. 

So the plan would be to refinance my primary residence to get a lower rate and decrease my Debt/Income ratio ( and just to take advantage of these low rates)    Then either 1) get a cash out Refi on my other property for ~ $65k to fund the down payment for a new home and get a decent rate on a loan OR 2) GEt a HELOC to use for the new property's down payment (and finance at whatever rate??)

It's true condos in that area do can take longer to sell, without much of a decrease in price.

Putting it on the market and hoping the market hasn't decreased, which it sometimes does.On the other hand, I've really enjoyed buying places and keeping them long term. 

I agree with @Chris Mason it will be nearly impossible without proof of consistent income over the past two years even though your rental income will decrease your DTI banks want to see the income. 

Personally I would keep in discussion with the seller, but wouldn't pull the trigger unless you have some favorable terms in there, decreased price, etc. 

And these numbers get even juicier if you benefit from significant rent appreciation or property appreciation, or if you decrease your down payment percentage.

Could a lot of investors quit buying properties b/c the mortgage will be too expensive, decreasing the # of buyers in the market, allowing cash buyers and owner occupants to have more opportunities??? 

That’s a great question, if rates decrease and you cash out refi into a fixed rate loan in 3-4 years then 25% down is a better deal, but only if you have the reserves and the risk capacity to cover if rates increase in the next 5 years.

You have a relatively brief window in which to do that (3 years before the benefit decreases, 5 before its gone).