I often walk past the, as you describe them "few shady-looking characters that hang around all day on the council estate by HOP station" and have never had a problem. On the contrary, one of the older chaps who sits on the wall always says hello in the morning as I walk past and is very friendly, I actually feel safer when they sit there than when they don't. Also, yes some of those flats in the building may be council owned and the building itself isn't pretty to look at (though improvement works seem to be ongoing), but it's not really an estate as such.