The not listing your collection thing;
I dont get that one. This is pinside, we all collect, trade, offer advice and opinions.
Why hide what you have? Some have more than others. Some have a one or two. Its what we do, buy expensive toys. Showing your collection I feel gives both a buyer and seller a little street cred when you go to do either.
Location; its a big planet. Showing your city with a forum name isnt going to bring a bunch of crazies to the house. Same as stated above, when you go to sell a pin lets buyer know if they should bother to pm you.
Show your collection and location with pride.