But they were selling an expensive house in California and had horrible credit.

To answer your questions here though:Alternative options - I was going to sell all my stocks and etfs, take out a HELOC, and some credit cards to try to shoestring together enough to the deal without a hard money loan. 

Of course credit card is going to be like 3.5% but it does kind of such because it's already hard to get tenants to pay it lol. 

Not for a single airbnb like you are seeking (you and everyone else) but because if you start a BNB or a guest house or a hotel, you can get 40% of your investment back in the form of a tax CREDIT that you can sell for about 90 cents on the dollar. 

Avoid PMI and then go to a local credit union and get a heloc after closing to gift the money back.Have this as a tool in your tool belt but pursue use of the 3.5% FHA, knowing that you will be at a competitive disadvantage if you are competing with non FHA buyers, then you can call in the favor from your gift person.Just know that if someone gifts you down payment money, your bank will require them to sign a letter stating that it is in fact a gift that doesn’t need to be paid back.

If you're using traditional financing on your primary residence, they're going to do another credit check on you just before closing.

Hey @Bailey Rentz, I'll say that we use QuickBooks Online exclusively for all of our Clients and they are constantly working to improve the bank feed feature and specifically the connections.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Use gap funding (credit lines, partners) for the down payment.

If you’re looking at retrofitting to separate heating for each unit (like furnaces or mini-splits), you might be looking at a higher upfront cost, but it can shift utility expenses to tenants and improve your NOI.I’d factor in boiler age and efficiency when analyzing deals and if it’s near the end of its life, negotiate a price reduction or a credit.