I really wouldn't have a problem with someone anchoring a bit off shore in front of my (at least for the night) campsite, but I doubt I would do that to someone else.  If I knew it was a honey hole, I wouldn't want to divulge it, and if I didn't know, I probably wouldn't bother fishing it.

As to passing by camps, we won't go out of our way to avoid them.  We typically carry on conversations while paddling, so I doubt we surprise too many people.  Usually I just smile and wave mid-stroke, as my default is that other trippers don't want much of a conversation.  However, if they are friendly enough, I'll stop and chat a minute.  Seems like everyone wants to talk on the portage trails.  That could be because they're catching a breath before going back, while we politely wait for our turn.