My future father in law is most interested in ensuring his daughter's interests were I to do this as a business full time, and leave my day job, asking for 30% of the appreciation of the value of the business or 5% of the appreciation of the value of the business if I continue to be an investor in the business as a "secondary" job.

Before you continue down the modification path much further I'd get in touch with someone who specializes in garage conversions or ADUs and get an approximate price and timeline and run the numbers again, it seems like you may be underestimating the cost, time, and difficulty of a project like this.

If you open your own brokerage, you will be in charge of marketing, hiring new employees, getting a space, the list goes on.Make sure you understand what will go into it, and if you think you can continue your success while getting some agents under you to make your business thrive. 

You're accelerating your education by constantly putting yourself in position to talk to people with problems, much faster, and on a much more consistent basis.  

Just getting educated about the process of buying an "assignable" tax certificate in Illinois and getting a tax deed if the buyer does not redeem.

., unless this "interested person" meets all your other tenant criteria, particularly having net income that is at least 3x rent, there's no need to even continue down this path.

I plan on continuing with the military as I do like the lifestyle.

I know thats an outlandish statement, but most people buy homes with no plan and do okay you have a plan and and your working to gain experience I figure continue the research, run the numbers, and follow through but thats just how I feel.

It may be a C-/D+ building but it’s treated me very well so far and I plan to continue acquiring more of them until I have enough equity to buy a large house here that I can break up into 3-4 rental units.

The process of completing the required education, PSI examination, and deciding on a sponsoring broker were all easier than I expected.