I want to know opinions of chyoo readers and editors. Can you enjoy contribution of writers who have their English far from ideal?
Just as Zingiber said, I'd make as little changes as necessary to the grammar without altering the content and accept it.
It really depends on how bad the typos and grammar are. It's one thing to have some typos and/or grammar mistakes in a thread, especially if it is a long one. It's another thing if there are so many typos and mistakes that I can't even figure out what the author means with some sentences. Fortunately the latter case is rather rare (at least in the threads and stories I read).
While I'm not a grammar Nazi, grammar does matter. I try to find the balance between readability and the fact a lot of the contributors here aren't native English speakers. Provided I can understand the thread, and it makes sense, I'm fine.