I don't know, I consider myself a new player, still. I didn't play HnH. I did watch some videos about Salem before I got into the beta. I loved the forage/exploration stage of the game. And the nomadic ad hoc settlements stage. I love the skill system, etc. I suppose I knew what to expect, and I had seen videos of the interface so none of that phased me. At this point though, there really isn't much to do. I have all the skills. I got my first prof to 100 the other day (not sure if I can go above that). I agree that there is relatively little options for things to do in the end-game. I eagerly look forward to new feature/releases. Anyway, I'm part of a small village now and we toy around primarily with concerns of defense, which is I think the main point of this thread, so back to that...
The issue with walls, and why building 5+ layers seems pointless is two fold. First there's diminishing returns on space/resources used to protect stuff and what you are protecting. Ignoring that, the main issue is that 6 walls are not significantly better than 3. I can already break a hole in a plank wall in a few minutes (admittedly not facing brazier "fire"), and I'm far from a high bile vet. Why spend weeks building 2 more layers of plank walls that will take a serious raider less than 2 minutes to break through. I hear people talking about spending hours breaking down walls in this thread. What hours are you talking about?
As for other suggestions in this thread,
Re: Coles
I readily recognize and acknowledge the wisdom of skewed gates... They just look horrible

(and I imagine are bothersome to drag sleds through).
The brazier wall brazier defense sounds fine until you have to reload one of your braziers (unless you are implying only one thickness of walls, in which case it's terrible).
I thought about a tree wall myself, but haven't verified if you can plant trees close enough together for a successful tree wall. I also imagine that would look most unnatural

.
A wall of auth objects sounds particularly ugly (and expensive), but sure

.
I'm not sure what a glitched stone wall is, but like the sled wall construction sounds like bug exploitation which I'm not especially enamored of (which I think was also your point in that part of your post).
Re: Chief
Bears despawn when no one is around, so they can not be used for an effective defense. I do not understand the value of diagonal hodgepodge of walls :/ Don't suppose you'd explain that?
For me, it seems that there is no effective defense other than anonymity (and luck).