My thought was that since I was simply loaning him money and wasn't otherwise involved that that offered a level of protection as well.  

@Elisha JohnstonFrom my experience, San Antonio is a great market for cash flow, with entry-level homes typically ranging from $200K to $250K and steady appreciation around 3-5% annually.

Do not think you can just start an investment company with 15k (that is reserves only on one property).Work for the next couple of years while you all learn and use your skills to help build the foundation of a future company and leverage your relationship with the alumni to see some of his properties and learn.

One of the reasons why I’m bullish on real estate investing is because I am more afraid of the “what if I didn’t invest” rather than the “what if it goes wrong.”Yes, I could fail and lose everything I started with, but I’d still be farther along than if I never started at all.I’d have the knowledge, skills, and lessons that only come from taking action.Every misstep is a step forward when you’re learning and adapting.The real risk isn’t failure, it’s standing still and letting fear hold you back.Take action!!!

I played collegiate football at Montana State, where I learned the value of discipline, teamwork, and persistence—skills that I now bring to my journey in real estate.

Try to reduce the number of problems you can think of to a manageable level, or instead of a 5 bedroom place maybe go a little smaller with a 4 or 3 bedroom that is generally more manageable and not pack people in like sardines.  

It’s great to have someone with your level of experience and diverse background here.

It's probably taken you quite some time to develop a level of aptitude through experience, and it's most likely, well deserved.

Read: The millionaire real estate agent; Hyper Local Hyper Fast AgentWhat are some effective ways to network with individuals at all levels?

The next level up is hiring a revenue management company or VA to do this for you.