There are other factors at play at Wikipedia too. In my native language, Danish, Wikipedia is all but dead. Years ago, I tried contributing within my own field. I researched and spent hours adding relevant information to different topics, only to find out a few days after that all my contributions had been deleted by the administrators.
Here is the Danish site for one of the most beloved Danes: https://da.wikipedia.org/wiki/Michael_Laudrup
Here is the English: https://en.wikipedia.org/wiki/Michael_Laudrup
It's just one example, but it is true for culture, history and many other areas. If you want to know anything on Danish matters, the English Wikipedia is usually a much better option than the Danish.
I've encountered torrent sites that make more effort to make newcomers feel welcome.
Never tried again, and won't, despite running across much that's inaccurate, plain wrong or has poor language over the years.
Yes, but a simple link to which article it was would be enough. What also might be useful is a user name and/or a rough estimate of what the time period was, but without even an article name, there is nothing anybody can do about fixing these things.
It was some hours I spent on a topic I knew well, and had a good selection of books on my own shelves to cite, triggered by finding an incomplete or missing article, or a glaring error. Nothing more. After the challenges contributing I lost interest and moved on. I was doing Wikipedia a favour and trying to contribute, they apparently weren't interested. I'm not going to fight for it, but as a result I'm not open for trying more, or ever again.
As for username, I have no idea whatsoever, but offhand I can only remember one of the several LJ usernames I had, some I used for months rather than just a few days. Mind I doubt I could accurately list all the topics I blogged about on LJ, either, but could cover the main interests easily. I'm not even sure a username was needed at all but it may well have been.