Where I live, no one messes with your stuff. I left my camera in my car on accident when I was at work one day, and it was in broad daylight (It wasn't too hot or too cold, though). No one ever messed with it, nor does anyone ever mess with stuff where I am. Most people leave their homes and cars unlocked, and people even tell me I'm paranoid when I do lock my car.
Anyway, my setup is my camera and that's it, no extra lenses or anything. But if I had accessories like what you described, I would keep them in a place where I could have my eye on them, like attached to my tripod, or even sitting underneath it unattached would probably suffice. . Burglars for the most part don't want to get caught in the act, so if they see that what they want is in your view, they won't bother you. Its when you turn your head that they start getting brave enough to try and swipe it. And they will wait for you to turn your head, even if it takes an hour, as long as the payoff is worth it in the pawnshop.
Note this philosophy doesn't work for robbers, just thieves. They are two ENTIRELY different types of people, the former being aggressive people either desperate or power-rushing, and the latter being shifty and scared of confrontation. If you meet a robber, give him your stuff and go, cause anyone who is willing to confront you so brazenly cannot be trusted enough to NOT hurt you if you don't give them what you want.