1. Nice looking terms that are not realistic with the current market. 

I am not sure why some investors still fall for this one. Everyone is after the lowest rate/ no cost/low cost loan. You will probably get this at a local bank or credit union if you have other assets invested with them, but not in the hard money/non-qm lending space. Lenders, brokers, and loan officers are in the business to help you get financing and make money. They are not going to cut you any favors and do your loan basically for free. What I see most commonly is Investors calling up a bunch of lenders or emailing them, plugging all the terms on a spreadsheet and going for the lowest one. I wish it was that simple, but you are not accounting for the fact that this industry is not regulated like a consumer purpose loan. You will very easily fall into the trap of a bait and switch if you don't actually take the time to research the companies and ask the right questions. 

2.  Getting the runaround (requesting more docs, taking longer than usual, or just simply not being straight forward)

This usually happens if you are working with a broker that doesn't know what they are doing. If you keep pushing back your closing date, and the broker is constantly going around your questions, this is clearly a sign that you may not close on the loan. Always ask for conditional approval letters and review them with your broker. 

3.  They have a do it yourself business model. 

There are a lot of lending companies and broker shops that have a do it yourself model. This is not good as you basically risk screwing up your own financing. An experienced loan officer is going to look at your file and ask for the docs he/she deems necessary in advance. This avoids you sending in items that will kill your deal or make it difficult for you to close on the loan.