I think you should do a bit more study on biophysiology. First...the ketones don't make the blood acid. The body maintains the blood Ph in a very narrow range which does not vary by more than a few tenths of a percent at any one time. Above that narrow range, you are acidotic with serious symptoms that require hospitalization and below that narrow range, you are alkalotic which again would produce serious symptoms requiring hospitilization. I have yet to see a person post on this board that they required hospitalization for either condition due to being in ketosis. I myself have been following a low carb plan for 18 months without any such problem and there are others here who have been doing it for much longer without such problems. I've also mentioned before Dr. Bernstein who has been living quite well on no more than 30 grams of carb per day for more than 40 years and requires his patients to do the same...again no mention of hospitilization for acidosis or alkalosis or heart attacks brought on by acidic blood. Heart disease, strokes and diabetes are virtually unknown among the Inuits who follow a traditional diet which is practically carb free. I'll leave it to you to research that for yourself.
Second...when you maintain that all a person has to do to lose weight is eat less and exercise more, you completely discount the effects of insulin production on fat storage and fat release. You also fail to take into account the effects of other hormones, medications and medical conditions that greatly affect how easily a person can lose weight even with reduced calories and increase excercise on a "traditional" diet as you call it. Many (if not most) of the people here on this forum, including myself, have tried that route and failed miserably but found success with low carb. Millions of Americans have diabetes which by its very nature means that they are insulin resistant and carb intolerant (hundreds of thousands more have the disease and don't even know it). Hundreds of thousands of American women have PCOS which, again, by its very nature means that they are insulin resistant and carb intolerant. You need to do more research on insulin resistance and how that condition develops; there should be plenty of references and studies for you to find on the web.
Since you're taking a creationistic approach, the Bible does mention seasons and snow. Paleontologists also have a pretty good idea what climates were like at various times by studying fossils for a certain time period.
Lastly...no, people who follow a low carb lifestyle do not live in a state of ketosis forever and ever, only until their weight loss goal is achieved. By the time that they have progressed through ongoing weight loss, pre-maintainanace and then maintainace gradually increasing their carb levels as they go, most if not all, are no longer in ketosis by the time that they reach maintainace. They have simply found the correct balance of carbs, fat and proteins to maintain their weight loss on a permanent basis. Many low carb plans don't even recommend going into ketosis at all (Protein Power, The Schwarzbein Principle); not because they believe it to be harmful, but simply because they don't believe it to be necessary for weight loss.
Fat burning occurs (assuming that you have a normal metabolism and no insulin resistance) when calories taken in are less than what the body needs for basal metabolic functions plus daily activities. You cannot choose when or how long that fat burning process will last even with exercise and lowered calories; your body will burn the fat when it needs more calories. Assuming that caloric intake in lowered calorie diets is evenly spaced in 3 meals and 2 or so snacks; negative caloric balance would be pretty much a continuous thing and therefore so would lipolysis. Starvation begins when calories taken in are less than what is required to maintain basal metabolic functions which freqently happens in most calorie restricted diets recommended today. For example, the diet recommended to me several years ago by a doctor was 1,250 calories a day...well below my basal metabolic needs. In effect, he was recommending controlled starvation for me and it didn't even work. If the body even thinks it's being starved, it responds by lowering metabolic rates to preserve what stores it has; so much for your theory of tricking the body into thinking it's starving through ketosis. Yes, people who are starving are in ketosis, but the reverse does not hold true. The presence of ketones are not what tells the body it's starving; the lack of sufficient caloric intake does which is why you will see frequent reminders to people on this forum to make sure that they are getting sufficient calories on a daily basis.