Not sure why people go for 40-year fully am instead of just traditional 30-year with 10-year IO option, I tend to think the 40 year term is more of a gimmick

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

It will co-exist with other "new" payment methods such as google pay, apple pay and credit card etc, because the target customers are different.

Traditionally most lenders will require 25% down, however there are a handful that can do 20% down without any experience. 

I have been trying to save up money but it is not near a down payment for a traditional loan.

Options ive looked at are the Burrrr method, house hacking with fha living in the property for a year doing small upgrades and forcing appreciation refinance then rent and repeat that every year until we reach our goal.

I'm in a beach area where Sat to Sat rentals have been traditional for 100 years, but not any longer since the rise of Airbnb (and less control by local property management companies).

We own 10 homes, but all the rest are traditional leases and are also close to our primary home in the Lake Norman area (all w/in 30m).

Why would capital requirements be any less than traditional development? 

-> Funding: you can consider as options mortage brokers who can scout/compare the best offers in the market and you can also consider public funding programmes that exists as an incentive to renovate and bring houses to the market, either for tourism or traditional rental.As an example, on the traditional rental there is a funding program ("Arrendamento Acessivel") that funds up to 90% of the project and can be used to cover part of the renovation costs, as well as, part of the purchasing.