If there’s an existing mortgage on the property, a subject to combined with a seller second, or a wrap around loan, carry significant risk and possible negative credit impact for the seller (and buyer).  

I am currently completing the pre-licensure course for my MLO license, aiming to become a mortgage broker specializing in primarily non-QM/hard money products, along with some conforming loans.

You can really mess up the seller's credit if you miss payments and they can then sue you.4.

Contrary to what social media real estate gurus (who are trying to sell a program/course) of "get started in RE without your own money using Other People's Money" that's a potential disaster. 

Yes of course the old saying "location location location".

It’s never a good idea to take a 30% or higher hit to your retirement funds when you can invest without any penalties or income tax ramifications. lol of course, but I do understand why he "chooses" to practice it that way. 

That being said, there a are a lot of great programs out there to finance investment property if you have decent credit and enough down, you should be able to finance a property that will cash-flow reasonably well. 

There are some lessons that can only be learned through experience, and A HH will provide incredibly valuable lessons that no mentor, real estate course, book or podcast could ever teach (though, I'd still recommend reading up on relevant RE resources, listening to podcasts, etc.).

One of the main advantages of course is affordable real estate prices (according to Redfin, the median home price in Dayton reached $115,000 ).

Of course, the rate can be slightly steeper than the conventional loans where it is a full document loan, where they need to qualify you based on your income.Alternative way, is to acquire the 2nd property as an investment property with conventional, while putting 15%-25% down payment.