Can’t they file a Suspicious Activity Report (SAR) for anything $5K+?  

I would be very suspicious of working with a contractor that demands from 40% to 50% down without providing me a justification or allowing for negotiation.

Hey Bryan, I would always be suspicious of anyone trying to convince me to pay more money( a whole lot more) for any service. 

I know the owner personally, and am now suspicious...

After speaking to him, I was informed that one of the family business accounts was closed due to suspicious activity.

But some lenders are more willing to work with folks in your situation vs. the typical lender who's never seen a case like yours and is stupidly "suspicious" because you don't fit in the box that they have in their mind for a typical borrower. 

I became suspicious after watching some “wholesalers” vids on YouTube.

[Once the world says "peace, peace", won't banks (suspiciously) find reasons to increase rates?] 

If it still looks good I get suspicious and I run it again a couple of different ways.

Do you ever feel suspicious of this statement, that it makes people believe that all problems needs must have a solution that doesn't require working hard?