I would not want to be to critical since I myself personally have my own difficulties with my pronunciation in english. I would never want to offend anyone. Just pointing out the more obvious misspronunciation of "quin". Regarding Cozumel I actually like the more native name Cuzamil but that is another topic. I appreciate it when someone is trying to learn and speak spanish when they are living here. They deserve all the help we can give them.
Your tips are much appreciated Morenita! And if anyone is offended by your offers of help, that's their problem, not yours. I for one am always struggling learn Mexican Spanish so that I can communicate better not just with service people but also my Mexican and Mayan friends and neighbors. It's also a respect thing, I believe. And, finally, Spanish, like Italian, is a beautiful sounding language. Very musical. I love the rolled r's!
Please keep the tips coming. In fact, I think I should start a learning and pronouncing Spanish forum on here! Will put on my list.