In general, investing at the business level (marketing, prospecting, hiring, software, masterminds, etc) will drive growth more than solely investing in physical real estate.

The next stage in the matrix is called land development which consists of horizontal physical improvements like grading soil, installing wet and dry utilities, street improvements and flatwork (pouring streets and sidewalk, etc.). 

I have a lot of land leads, but they don't have a physical address, only a TAX ID.

Option 4 can only work if the exchange funds are used to buy the real physical property that the business uses/is housed in.

That deposit does not have to be all cash, it can also be a pledge of some other asset such as a car.Lastly, if your last tenant left you with damages (either physical damages or failed to complete their lease obligations), the security deposit you kept may or may not have covered that loss and you should be entitled to seek a judgement against them for monies still owed.

On the other hand, have you thought about going in as an LP on a syndicate so you can see how the process on larger multifamily works, how they analyzed and underwrote the deal, how and what type of financing they got, due physical due diligence with them, raising capital, closing, and ultimately hiring a PM company to reach your objectives.

Deshone - your rehab costs will depend on the physical condition of the property.

So you need to think about a small business loan as much (or more than) just buying the physical property.

I found a great cloud-based brokerage that will allow me to train without physically being in the office taking leave from my military position.I think about finding a brokerage like going shoe shopping.

They are about $40 bucks for the twin double pack for the unitIf you can afford it and want to go one step further, you can use the "smartkey" type locks so you do not have to physically change the locks.