The low inventory issue at least partially stems from the fact that those who live here can sell a house in a few days, but don't feel they can find a new one at any sort of a reasonable price.

I live in Colorado where cannabis is legal.

Guessing, 80 % of the questions on this site stem from the lack of understanding the basics.If investors were aware of these basics, you could read any guru book one time an get it.

(I would assume as long as you are under the roof, it is fine) Again I have never heard of so, and I know this stems off of what was originally asked, but I figured Id ask. 

The first issue I am running into happens to be initial capital for investing, and this stems from my fear of taking on an initial loan for a down-payment on a property is this a good idea to do or bad and why? 

STEM + Accounting/Finance are the easy route to having an easy, comfortable upper-middle class life without breaking too much of a sweat.

If this helps, it basically stems from the question I've been mulling over lately, 'if one of my property becomes vacant, how will it impact my other two properties, and how much of the cash flow from the other two properties can I use to offset the costs of the third?'

Statistically, college for 4 year STEM degrees is still a great investment.

That's another story for another time but my question does stem from it:Is it common practice for investors to exchange commercial brokers (contact information)?

While Capital is imperative, that is not the stem of your problem.