You must have been burnt an awful lot. That's a very restrictive set of "rules". Talking on the phone is no guaranteee. I've seen people insist on that because they thought they could tell hucksters and charlatans by voice. Let me tell you that you can't. If they're a "salesman", they will "sell" to you by voice, in person or through email.
FYI 3 days for acheck to clear does not mean it still will not bounce. Out of state checks usually take 5 days to bounce, but it may take 2 weeks before the bank tells you that it bounced. Been there; done that; been screwed!
I do understand why you're doing this, but ...
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"We get old too fast, and too late, smart."