Apparently there seems to be 3 major issues with the content of the wiki: spelling errors, grammatical errors and factual errors. This page is here so that some down-to-earth solutions can be presented to all wiki authors so that we can avoid making errors in the future, and increase the quality of the content.
Spelling mistakes are the easiest of all problems to correct. I have taken it upon myself to ensure that for any page I edit, I spellcheck the entire page. As mentioned on the wiki-conventions page, there is an extension for Firefox that can help. Other authors are encouraged to do likewise.
Grammatical errors are a little harder to deal with. Obviously small errors like forgetting to capitalize the first word of a sentence can be dealt with by simple proofreading. However, wikipages are written by people with different writing ability and style. How do we account for this? Do we? Should there be a CSW spelling and grammar test, where you can only contribute if you pass?
This leads to the question: "how should wiki-pages be crafted?" Should each wiki-page be viewed as an essay, and be held to the highest standards of English language? Should they be viewed as long term conversations? How fast and loose can the language be?
That depends on the page in question. If the page is intended to be a useful reference or a tutorial or something of that sort, it should read well, it should be meticulously proof-read, and it should certainly not look shoddy & amateurish. If it's a page such as Kali-Scheme-Revival, which is intended more as a message than a resource reference or something, the content would obviously be informal, and there is nothing wrong with that; and, for comment messages (like this one), any level of formality of content structure makes sense.
Another very important question is "how can those with a lesser command of the English language improve their skills?"
Those can improve their skills by requesting English pedants (such as myself) to proof-read any pages worth proof-reading (as I clarify above) and note & correct any errors of English usage & any bad style.
Another issue is that of content of the wiki being just plain wrong. What can we do about this? One cause of the problem is that the initial page authors may not be as knowledgeable about the issue being discussed as others. Should these authors refrain from writing any content at all? Should they write a stub page? Should they just try the best they can, and hope that someone with more experience and better knowledge will help them out?
A smaller issue is categorization. If you are confused about categorization don't categorize it. An enterprising wiki-gnome will do it for you. Try to categorize new pages or categorize uncategorized pages. Categorization is optional although recommended.
The most important thing in all of this is to remember that this is the community Scheme wiki. Wikis thrive best when there is a community around them.
Such grammatical errors can be fixed by the community as the wiki evolves. My problem was not in the existence of grammatical errors but in the complete apathy in correcting them -- correcting them before the creation of content or as people continue to read the content.