I guess the only way to find the truth would be to do all the tests yourself, but I think some are false, such as the police carrying coke. Maybe one or two cops did that. The original book those tips appeared in would also be interesting to read, because then you could compare the two and see the direction that the author of the later article was pulling you.
I know it cleans copper coins. You can try that one yourself. But I think vinegar does as well, it's an acid.
But all things aside, I believe coke is extremely bad for you. And I can't do any of the experiments because I have no coke in the house.