I think it's probably a result of a number of BP youtube videos about this exact subject, making it sound totally doable with the right team etc.

@Tanner Marsey that's great insight and I am definitely coming to the realization of what is doable and better managing my expectations and seeing what is plausible.

It’s a much smaller pool, but certainly doable.

Finally, I would prefer to be $100k w/o my retirement pay, but if that’s not doable, then I should have an additional $30k coming in which would only require $70k. 

Obviously you have to prove that you can responsibly handle that amount of debt by never missing or being late on payments, but if you are responsibly paying off that debt than it will increase your score.For your next purchase, you will not be able to use the FHA program again unless you refinance your current duplex into a different loan program as you cannot have more than 1 FHA loan at a time.However, using Fannie/Freddie as a conventional loan is completely doable.

I would go with all cash, if cash out refi on conventional non owner occupied 4 unit property was "doable" in this day and age.Thoughts?

But the 20% is a good target for you to shoot for in regards to equity capture, and is very doable if you buy right.You are going to have the greatest potential for equity capture by buying right on the front end: (1) dealing with a distressed/motivated seller, and/or by (2) dealing with a distressed property, preferably both.

If you are tech savvy and have tenants that are B-class or better than it’s doable regardless of distance.

A goal of $1mm net worth in 5 years from zero is doable, but rare.

That seems doable.