Alright guys, heres what I think. I have fished for many years, plus am studying biology right now in college. There are going to be bass that spend the majority of their time doing all three. What people have to understand about animals is that they behave just as people and other animals do. (including fish) Bass do move shallow to deep and back to shallow, its proven fact, and people catch fish because they know these patterns. However, just like you and me, individual fish can prefer certain areas over others, spending a majority of their time in cerain areas and its actually easy to tell which ones are which, especially during the summer. Now obviously fish arnt going to be in 2 ft of water in the winter all the time, thats just plain stupid. (not sayin they may for an hour or something but you know what I mean) But for example, have not you ever caught a fish that is so dark its almost weird? The pigment in a largemouths skin tans just like a humans, and odds are that fish spends more time shallow then others. Later on your fishing down the bank and you catch one thats dang near white. Odds are that fish is one that prefers deep water, that may have moved up just for a quick bite. Youll notice in waters that are deeper, and clearer, where the fish would naturally be more likely to go deep, that they are lighter in color, whereas waters such as ponds and lakes with muddier water, fish move shallower easier cuz the sun isnt as big of a factor to their eyes. But the UV rays still can get down through the water and tan them to a darker color. Well now that ive explained how fish get tans in detail, all I am really trying to say is that fish do move, but the majority probably do prefer something more then something else, its natural for living things. Some people like moutains, others beaches.
This is my input anyways!
PS..... o ya and the spawning thing, thats not really an issue, some fish spawn later and earlier then others. (another preferance) Also, largemouth beds can be found as deep as 15 ft (from what I have seen, maybe more?) when conditions are right, so they could techniqually stay down there if they felt like it. But like I said they still may go up now and then, just prefer the deeper.