I should incorporate right away (or when I'm getting close to buying my first building), for a few reasons:- liability protection- establish the business (and its creditworthiness)- looks professional, as it should be if I'm going to own a quadplex, and then maybe more buildings later (presumably all buildings can be under the same corporate name)As for financing, hopefully by the time I need to apply for it, I will have established a good credit reputation and have solid financial statement to qualify for financing or even a business credit card.

Despite what many will say, in my experiences you will need to have a strong balance sheet, be credit worthy, and bring value (IE experience) to find quality partnerships or invest successfully in RE. 

Rates are currently averaging around 7% or higher most of the time right now (insert disclosures about creditworthiness, etc. here).

I went from the low 500's to almost 700 in a little over a year and i'm at the point in my life where i feel credit worthy now.  

I've only in recent months decided to pursue real estate investing and I want to be maximally positioned as a credit-worthy borrower.

Even if there's a small chance of getting caught, I'm not going to risk 18 months in the clink plus big fines and having my loan called plus ruining my creditworthiness just for a lower rate personally, but I'm not a gambling man. 

I don’t want to mess up my lender credit worthiness but if the student loans are paid ahead and no payments are required, it would be nice to build a larger cash reserve.  

I agree SFH are more risky for investors based on your two points, but we are in a prolonged SFH shortage, and homes are the gold standard of rentals so only the best creditworthy people should be renting them. 

You’re probably looking at a half a point or more depending on your credit score/credit worthiness

Assuming seven years remaining and you want some margin of safety against rising rates and the fact that you don't know a lot about the credit worthiness of the borrowers (though you should see their files as part of DD) I'd have a required return of at least 14% so that makes the notes worth about $73.5K Another option is not buying the notes at all since you don't know if they are SAFE act compliant and you can avoid the hassle/risk.Total price: $330k-$450k, but you'll put finer point on that once you get into DD.