However, I also have student loans of 123k with fixed interest from 4.3-6.3% and a car loan of 25k at ~8% rate. 

Yeah the area that we're investing in has good Section 8 rates and we're starting our research to see if it's worth it.

With what we have, we could pay cash for those properties, so that we can avoid the high interest rate nowadays.

Citizens Bank offers a competitor rate - Also a bank with an existing relation ship will offer you good terms.

Bought my first house (primary residence) in Denver, May of 2021, 3bd x 1 bath, for $525k with $85k down at an interest rate of 3.25%.

With a typical LTR property @ 7% cap rate someone would need to buy with either cash for about 7M to get $500,000 cash flow or it's equivalent of equity if leveraged? 

The proven additional cashflow may compensate for that a bit but that will be largely priced in and you may even need to discount the cap rate at sale. 

The mortgage is assumable upon their demise (and at a rate lower than those currently being offered).

Or, commercial airline pilots who have either paid a fortune for aviation training from primary, multi-engine and transition to heavy jet type ratings or served in the military and gave up many years of their lives to serve their county.For a great discussion on the value-for-value read Robert J.

I have been reading Long Distance Real Estate Investing - David Greene, and came across an interesting tidbit of information: Your first 10 (1-4, 5-10) property loans are Fanny Mae insured, after which your loan criteria become more unfavorable (variable rates, stricter credit score requirements etc.).