Just wanted to say some excellent work so far. You continue to impress me with what you're able to do with this engine.
I think un-scope while moving is totally fine. A few games have done this and while Turok is a fast paced shooter, sniping is something that you'll probably want to do while at a safe distance. It is a sacrifice for being able to shoot foes from afar. I think it balances out pretty well honestly. Players will figure it out within a few seconds and there really isn't much to worry about. Auto re-scope after you're done moving is also totally fine. I think its a nice compromise. Though, I'm one of those "power users" and I prefer to manually re-scope. I think players who are looking to snipe, can accept being un-scoped, moving into position, and re-scoping. It can be jarring if you don't expect it to auto-zoom again. But I think players would also get used to this.
So I think either of these two options is perfect. Entirely subjective preference to which one a user would prefer using.
However for the last one; it is a novel idea. But I think its a no go. Moving around just causes non-stop flashing. Try it while strafing, or strafing and jumping! It is visually distracting and uncomfortable to watch.
As for the AR + GL. I think its awesome, totally reminds me of Half-Life, its also something I wanted to do with my own projects.
If you want a custom model, I can whip one up real fast.