Pretty easy to nullify (or secure) an agreement with this kind of language.

You may need a separate bank account to hold the security deposit, for example of the latter. 

I'm currently just waiting for my PMIC license to be issued before officially launching the business.

By having positive cash flowing investments you can begin to replace your active income, as well as take advantage of appreciation over time to leverage that equity to acquire more properties - and you can take advantage of all of this while using the bank's money to secure assets! 

Overall, the experience has been great and I've officially been bitten by the "Real Estate Bug."   

But what if I were renting a single-family home on three acres with no neighbors in site and this guy offered to pay me a year in advance and a $20,000 security deposit?

I carried over there lease and security deposit with the purchase. 

Got a college student for a tenant, (SC State), Father paid 6 months up front + security deposit, for a total of 7k.

Then have them complete the official application with background and credit check (through zillow?

However, we had secure jobs lined up and had predetermined that our quality of life would not be compromised by moving.