I'm scheduled to close in less than three weeks and the deal seems like an great start to my budding real estate career.

Is this going to be a one off deal for you, or do you plan to start an REI career? 

How stable are they, what is the historical trend, and what are potential threats to future earnings?

but you need to read your local laws and never think the prepaid rent is your before its earned... 

That's likely what's happening here to you, or they have a legitimate concern with these exposures due to losses they've paid out in your area over the past few years.The good new is that there are many carriers/agents that would love to quote/earn your business and keep it for years to come. 

I'm currently a sophomore in high school and I want to pursue a career in real estate but I'm not sure if college is worth it for the type of career I'm interested in.

Individuals can find many different opportunities to earn income in real estate because it will never go out of style.

To Sean’s point you connecting with a local PM is a great beginning to a wonderful career because of the value it brings.

For the contract stuff you should talk to a lawyer about that and someone already utilizing the strategies you are discussing, know the risks of the strategy you want to implement before moving forward and maybe try to shadow someone already doing them.Again my initial recommendation is that you put your work ethic and drive toward something with a more predictable payout, stop wasting hours working for Walmart, bring your earnings up and continue learning about this industry and then make a move for something bigger once you have a nest egg built up and have taken the time to develop enough skills to make it in whatever you decide to pursue.

What are 2 things you would've told yourself at the beginning of your landlord / property manager career?