You are right to be suspicious however, they could definitely try to go behind your back to get a deal done with your seller.

Asking all cash in and of itself I don't find suspicious or noteworthy.

They knew we were becoming suspicious of them, especially when the President of the bank, who was in charge of our loan, and his assistant, were suddenly retired and fired with no explanation.

Why is this starting to sound somewhat suspicious as it pertains to your intent?

If I was a Loan Officer, I would be looking very suspiciously at a couple who wanted to have 2x concurrent FHA Loans, with a COMBINED equity of just 7%!

When sellers tout % returns it always seems suspicious to me.

I let them know who should be there and at what times and ask that if they see any suspicious characters to notify me.

I would be very suspicious and ask lots of questions as to why the seller made the choices they did.

Is the same privacy lost when a bystander writes down the tag number of a suspicious vehicle? 

Definitely don't give a check directly to the wholesaler without a deed and be suspicious of any title agent saying this is ok to do.