You guys think the "the Coming of the White Worm" is really about mans struggle to survive during the ice ages ?
Was their anything ever written about how Smith went about writing ?

No, to part one -- it is not unusual to read into any writer's work things that are not there in the mind of the author - but that's OK - If it launches you into another realm of understanding of your own -- ie. different pianists may interpret the same piece by Chopin, Bach et al differently, finding in it as it blends with their world experience, dynamics and meanings not in the mind of the genius. Genius is not uncommonly greater than he who possesses it.

In answer to your second question: If you have the opportunity to examine his manuscripts, many of which, including mine, are in Berkeley at the UC - chap named Black can help you out. However, fundamentally, he received ideas from the various circumstances around him - an old water wheel, abandoned dark mine, deep dark space,
the Happy Hour bar and its denizens, his wide reading etc, etc. He generally began to write and let the work flow from there. He made few corrections, but was not averse to doing so - like Mozart, most of his work wss pretty much composed or at least outlined in his head before he started. To my knowledge he never made "outlines" of his work before starting - examine his unfinished work and you will see that this method can lead you into a corner you can't get out of occasionally - Clark never wanted to write from necessity, which fierce angel drove him into the prose field.
Had he had independent means, I doubt a single prose tale would have ever come from him. I am grateful that he wrote them, but having to deal with editors and publisher's demands, and then having to beg, cajole, and bully them into paying him was a dimension outside his nature which he was forced to adopt. His bit of advice on writing which survives in the "Sword of Zagan" collection reveals some of what he learned from bitter experience.

I hope this helps - If you wish to be a writer, Clark would have said, "write!"
There is no other way to learn this craft. If the fire doesn't burn within to do it, felt as a need as profound as food, clothing, shelter, and love - don't.

Excelent answer thank you very much, I have been reading some of the letters and other miscelaneous writings of CAS on the site and they have given me some great insight. Soon I will buy the letters Arkham House published and try to procure one of the few biographies written about him. I am still financially recovering from a buying the "Weird Flower" drawing by CAS.

Thanks again