Having different phone numbers, different email addresses and different addresses would be suspicious, at least in my eyes. 

Most people would be suspicious of you check the "assignment and removed from liability" box.

My question is lender A requires 25% down,($168,750) 5/20 ARM with rates starting @ 5.25.Lender B says we can do 10% down, ($67,500) 5/20 ARM with rates starting @ 4.25.Should we be suspicious of Lender B?

I would be a little suspicious as to the reason why.  

We all noted that the winning party had not been present with us and seemed to show only to meet this particular lawyer.Summary: a group of bidders suspicious that auction lawyer may have arranged a deal with buyer ahead of the auction. 

Shortly after, he started flaking on the mentoring and I quickly became suspicious.

Don't know where the two appraisals will come back at but I told my buddy I'd find it highly suspicious if the appraiser that asked for his purchase price comes in much lower than the other appraiser's valuation and very close to the previous purchase price + 10% that the lender THINKS the buyer should be selling for because they don't need to make that much money off this property.

I find 5 adults to be suspicious, as well - sure, snowbirds come to the area, but they can find better deals than $6400/mo, and I would assume they typically come in pairs or alone.  

However they are naturally suspicious because of the ease of number manipulation basis shifting and step transactions. 

It's suspicious though that there aren't any short-term rentals ("STR") listed on the platform you checked out.