Weeping Angels have opened doors & have locked them, too, when they were unobserved. In "Blink", for example, they had no trouble moving around the house (when nobody was looking). They opened the roller door of the police garage to remove the TARDIS (again, when nobody was looking). The reason they couldn't get into the TARDIS was that they never had both the TARDIS & the key at the same time. Of course, we never saw them open doors, because we never saw them move at all.