Have you sent it yet? It's too long IMO keep it simple and to the point, plus be more polite. Something like
Hi thanks for you article on Wikipedia, there are a couple of misconceptions that I would like to point out.
Users do not "suggest" corrections, they simply _make_ them. There is no "editorial group," or rather the editorial group is everybody, and new articles and corrections do not undergo any _prior_ approval process.
You say, "If you find an error, you are welcome to suggest a correction." Not true; if you find an error, we encourage you to "be bold" and simply correct it yourself. You do not even need to create an account to do this. The link on every page that says "edit this page" means exactly what it says. It's _possible_ to suggest a correction, which is what the "discuss this page" link is for, and _advisable_ if you're not sure or the topic is highly controversial, but it is not necessary. If you see something wrong in Wikipedia, just fix it.
You say that "An editorial group decides which corrections and contributions merit posting." This is doubly wrong. First, this suggests that things need to be approved _prior_ to posting. They don't. Anyone can create a new page or correct any existing page at any time.
Second, there's no "editorial group." Or, the editorial group is everyone! It's a weird way of working, yet it does work.