This isn't really an etymology site, and neither is it a linguistics site.
As you know, I'm not one of the users who voted to close your question, but I don't disagree with what they did.
The reason is pretty simple: the relationships between the various meanings of as could easily be a chapter in any good textbook on the English language.
Also, differences/relationships between words are far, far easier to explain than relationships between a word's meanings (vagueness and ambiguity are much-studied phenomena in linguistics.
As FumbleFingers mentioned function words have little lexical meaning, and generally relate one part of speech to another.
So yeah, it really is too broad at the moment in my opinion.