On ze worldbuilding argument: What I try to do is read my scenes as if I didn't know anything. Example: Character picks up some sort of communication device. If I can read the scene without asking "Well, why did she use that weird thing?" or "How does that complicated mechanism actually work?" then I don't think it's necessary to add details about the functions of the device (even if I, as the omniscient author, know everything.) That's why having 1streaders is important. They point those out.