While as far I'm aware correct grammatically, your last paragraph gives plenty of hints that you're non-native: "If any American English native SPEAKERS HAVE [picky] time on their hands, I'd be grateful if you COULD tell me ("let me know of" maybe) ANY differences between my WRITING [big one here] (you can click on my username for an archive of my comments) and THAT of an educated native American English speaker.
There may be subtleties in your sentence structure that you'd be better off asking a linguist about; but you definitely come off as both educated and non-native in skimming.