I daydream about retiring early and being financially independent, but I know I have to front load my efforts in the next 10 years or so to reap the full benefits later on.

Don't underestimate the benefits of truly loving where you live. 

There is a cost of entry to obtain your license.....school, exam, licensing, hanging with a broker, MLS fees, lockbox key fees, Realtor association fees, etc.However, the benefits are vast for investors as you get real time access to mls, and access to properties at your convenience with your lockbox key.  

I understand that some education you have to pay for but with all the free info out there now what is a benefit of paying a person to teach you.                                                                                                        

Frankly at this point not much. once you miss mortgage payments your credit is hammered.next worse is to actually have a foreclosure .. not sure if deed in lui piles on or not.the benefit of selling to an investor is they should get some money to do it.if your not offering any money and just saying its going to help your credit your not going to get very far with that strategy. and if they are under water to where they want to give them back.. why buy them at all .. you would want to try to do a short sale so you got some equity.

Should I just buy it under my name instead and not do owner financing or would there be a benefit since he's willing to do so?

What's the benefit to you to remove them from the lease?

If there is no gain recognization because of 121 exclusion, there is no benefit of paying yourself a commission because you do not use commission deduction against your gain but you get taxed on it (again).   

Keep in mind this is ONLY a benefit if you previously received a 50(a)6 loan and you want to receive a HELOC loan on your primary home.2.  

The benefit here is it subtlety fixes the tax problem you are experiencing.