More importantly, a GOOD realtor who takes your criteria, financial situation, short-term & long-term goals into consideration is going to be a huge asset to your REI career. 

My understanding is that the contract for deed has the same due on sale clause risks as a subject-to, and gives me less legal protections.

I set up my Solo 401K trust (Which is NOT subject to UBIT) through @Dmitriy Fomichenko at Sense Financial and he's very knowledgeable this subject. 

I have been working in the financial services industry for almost 10 years now and thus had quite some exposure to other areas of investing (from private markets to public markets).

Buyers and sellers in commercial need you, as their broker/agent, to help them make financially intelligent sales and purchases and to really make your mark you need to be very well connected.

Worst case scenario it is your own asset, not marital property, and can help you out financially if you need it.

I am thinking about starting with wholesaling so I can fully learn the ins and outs when it comes to real estate investing with minimal financial risk.

My goal is to eventually gain financial freedom (teachers generally don't have this option if they only teach!)

You might need to consult with an Attorney or CPA to determine your type of company to keep you personally protected, a pre qualification letter from your choice lender, and your primary Team members.  

The language in my contract protects me in a number of ways.