Since I'm taking such a cash hit, I asked the sellers agent if they would be able to designate some portion of the sale price ($200k?)

Then you'll need to find land, acquire it, find a spec home buyer and set up meetings to design plans or buy a set online with mods.

A major part of the success or failure of an STR investment is the design, furnishing and management plan.

We will then, as the units turn over, get rents up a good bit further with additional design improvement renovations and hopefully reno into lower interest rates when they drop or at the very least in 5 years on our 20 year we'll have paid off enough to refi into a smaller loan.That is the only kind of smaller deal we can find in neighborhoods where we want to buy now. 

You can stack your personal 50%s up for separate ventures while still knocking out deals without your own capital2) Read Raising Private Capital by Matt Faircloth3) One LLC with the S Corp designation to pay yourself a reasonable salary from the flip profits.

Airbnb dynamic pricing has ruined the whole industry.Airbnb's dynamic pricing isn't designed to get YOU a booking. 

BiggerPockets is full of resources designed to help you along your journey, whether you are just getting started or a seasoned investor.

Then plan and design how you're going to deploy that cash via what strategy your wife and you have confidence in.I use a excel or google doc and my first sheet would layout all of the details of the sale including all costs that go into getting closed.

The interior is a total gut: new insulation, sheetrock, plumbing, electric, kitchen, bathroom, doors, windows, and landscaping.

There's plenty of companies who design and install for contractors for reasonable prices.