PH: You may be right in regards to the Wiki. You even have to request an account from an admin if you want to edit, which surely keeps well-meaning editors from editing. It's a shame, but if you remember the trouble we've had with bots spamming all across the Wiki recently, you understand why it's needed. As for HLP in general, including General and Political Discussion, I'm not sure, but it's not my area, so you need to ask someone else.
It doesn't hurt to have written rules as long as editors remember they are not set in stone, and some exceptions are permitted. Of course, it leaves room for subjectivity, but it's ultimately better than religiosly following the rules and reverting otherwise useful commentary because it's not 100% in line with them.
[EDIT]Also, we don't have guidelines for writing campaign/walkthrough/fiction articles, because the has not been a reason for them, so it's good. The Vet Comment policy is a different matter. Personal anecdote: I had to re-read the policy to understand why my "The Anubis is the TIE Fighter of FreeSpace"-kind of comment had to be edited out, so it's helpful for have it.
Mobius: I tried to address that, hence the suggestion to require people add references if they think their additions are not understandable for everyone.