Most
lye calculators that include KOH are designed around Failor's methods, including but not limited to, Brambleberry, Summer Bee Meadow, Soap Calc and even the Soap Maker 3 program. Even the gentleman of Candles and Soap explains why her recipes are "so lye heavy" as you put it: because KOH is 10% impure , containing also water plus a small fraction of impurities. To say that her explanations are incorrect, is to say that several other notable liquid soapers are wrong. And these are notable folk that we as liquid soapers turn to for the most accurate information possible.
No, the alcohol isn't needed, but it is a possible method, that yields different results. And in theory, her alcohol method can be synonymous with the glycerin method, in that glycerin is an alcohol by nature, but rather than adding it in, like with Isopropyl or Ethyl alcohols, glycerin replaces water completely, without the effect of soap expanding as it does in Failor's alcohol method. And you gain the same, if not better, end result with the Glycerin method. I however do not recommend the glycerin method for a beginner LS maker, because that method causes soap to go through its phases faster than the normal water/lye method. It doesn't allow a soaper to see the phases as you would when using water. Even just adding a little Glycerin to the batch causes acceleration of saponification.
Soaping 101 is also a great resource for beginners, but I've noticed some of her tutorials to have a few fallacies that can confuse a beginner, who hears or reads otherwise from other sources.
And here is the article that explains the lye excess in Failor's methods:
http://candleandsoap.about.com/od/liquidsoap/a/lyeexcessliquid.htm
And this on neutralizing the soap using either Failor's or SBM methods, both of which I already indicated, go hand in hand:
http://candleandsoap.about.com/od/liquidsoap/a/neutralizeliq.htm