As long as you can show there is enough profit for you to pay the loan back and/or provide them with a cut of the return you should be good to go.The flip budget is the biggest thing to tackle because if you are off more than a little it can quickly take you from the black to the red.  

It's been up for sale since 2009,Giant red flag.

All of the negatives you mention are red lines for me.

The other thing to keep in mind is that there are also portfolio lenders around who have 5% down products that may be worth exploring, possibly less red tape.

A lot of red flags so we backed out. 

Definitely a red flag.

Is there a stop sign or red light there currently?

For example, HAI in one of the markets I'm looking at is 245 . is this a red flag?

Unless there's a septic problem, tree root, etc that would have caused the clog. 

Anything that I should focus on from the start, or instant red flags that are show stoppers?