FHA is for sure not going to be an option for him, last option is purchasing from an investor with owner financing, or lease to own program where he will not need traditional financing. 

.- The 203(k) will allow you to bid on properties that need repairs that won't qualify for a traditional mortgage => less competition => better purchase price.You will need to find a great local contractor you can trust to supply the required bids to qualify for the 203(k).- After closing, you can do some of the work yourself to save money, but the program doesn't allow you to pay yourself.You will want to buy a Class B property, maybe Class C+, in an area that seems to be improving.

Just a follow up question, were you utilizing debt to invest, I have always been taught since a young age to try and not utilize debt (I come from a family of stock market investors, traditional business owners) where debt is not utilized as frequently which I obviously understand debt can be a very powerful tool and utilized in a great way its just something I want to avoid with my investments to an extent any suggestions for investing without debt or as little as possible. 

You will owe monthly payments until you fix the property up, rent it out, and refinance to a more traditional 30 year fixed rate product. 

I agree that DealCheck (or the BP calculator) does not provide enough tools or functionality to analyze those types of transactions (yet).But I would argue that it does a great job at analyzing more traditional buy & hold SFRs and multi-families, as well as flips and rehab projects. 

Is STRs the way to go in Hawaii or maybe just traditional LTRs instead? 

Can they be listed alongside other traditional MLS listings?

I have used both Traditional (pre-tax) funds, Roth and HSA.

Two of my units will be vacated in the next 2 months so this is a good time to consider this over my traditional 12 month leases again. 

A couple of years back they even cancelled holiday lights traditionally displayed in a large local park.