Training trash and treasure

Having been training in some systematic fashion for a couple of years now, I have come across a lot of ideas, either from others or in my trawling of the training "literature". I use the term literature loosely, for come from the field of medicine, evaluating scientific literature is just part of working life. I can tell you that of the medical literature, at least half of the papers that you read are just plain worthless, half of the rest are critically flawed and you might get an idea of something that is useful but you can't be sure, half of the rest is sound but the answer you get is only useful in a limited fashion. The remainder is genuinely useful on a day to day basis- and I am being very generous. Now... the training literature is generally written by folks who do not have the dollars (and subjects) available to them that medical researchers do, and seem to have a limited grasp of statistics and even how to ask a question that can be answered. So... most of what you read is nigh on unintelligable. Unfortunately it is all we have.

Questions I think are interesting and worth answering:

What is the real benefit of "base KMs"- once you have been riding for a period of time, how much and how frequently do you need to include them in your training? It seems to me from anecdotal experience (what much of the literature seems to be based upon) that less frequent high intensity work can maintain fitness and high performance, in a much more time efficient manner. 

What cadence is optimal for a given circumstance? There seems to be some suggestion that higher cadences are better for shorter events, but may even be deleterious in longer events. How much individual variation is there in optimum cadence?

What is the most reproducible and meaningful measure of lactate/anaerobic threshold? It seems to me that there are a ridiculous number of ways of calculating this number, many of which seem pretty arbitrary. What is the significance of 4mmol of lactate, anyway?! Why not 3.98 or 4.23?

Which situations are watts/kg more or less relevant? Clearly in flat events, weight is less important than sheer power and aerodynamics. Yet everyone bangs on about power to weight for everything. I would like to see a relationship expressed as a graph or something vaguely meaningful.

This is just the beginning of the questions that I ask myself. Don't even start to go to nutrition and tapering/pre-event preparation...