Don't really argue with you on most of what you mention. However one thing that I have noticed that is inconsitant with your post is the issue of.

"1) All of the machines have the same chip for payout and play the same. (came from a good and reliable source involved in gaming in Las Vegas)"

I don't know personally if that is correct or not, and I can't say first hand that you or your source are wrong, but I can say, simply, from my experience it doesn't seem to be totally true.

I have had experiences with specific machines that seemed to pay better than others. the example of The Orleans for example. There is a machine as you enter the casino from the hall leading to the rooms and gift shop etc. Then, there was a machine as you would exit the coffee shop, over by the sports book. The later machine is no longer there but I could, dependably, get 2 or 3 tokens on $20 from that machine whenever I would play it. I can't remember the reels but I think it was an older looking machine that simply had bars on it. Single, Double and Triple. Triple, Triple Triple would give you 3 tokens, Double, Double, Double would give you 2 tokens and so on. The other machine, as I recall, seemed a little newer and had 7s on it along with Cherries etc. That machine just seemed to be a lot more difficult as it could easilly eat up a $20 or two without paying anything. Now, as I said, there is only the one machine and that is the one that has always seemed tighter. I do have to admit though that I hit for the first time ever, on that machine, on my last trip back in June. Over 6 years of staying at The Orleans I hit it for about 4 tokens. I can't remember how much I put in it last time but I know it wasn't a lot and was probably more than 1 $20. I got an Al dressed as Statue of Liberty, Al holding a Checkered Flag, Al Bowling and I think one other that I don't recall right now.

I have also played the machines at the airport that seem to give out multiple tokens on a $20 while at Desert Inn one time I put $60 into a machine and didn't get a single pay out of credits or tokens until the last spin when I got 1 token. That was one that showed a golfer on one side and I think the Sheraton logo on the other. Odd thing, it was long after Desert Inn was no longer a Sheraton if I recall. Right before they closed in fact.