Well, it sounds like you've come to the right place! I thik you'll find that this forum is an endless spring of knowledge, information and wisdom on the subjects you have mentioned (and countless others).
I too have heard people refer to the salvia experience as "dirty" and "evil", but most of the people I have heard say these things were using the plant with the sole intention of "getting high". I agree that the effects that are brought on by these plants and compounds can be extremely dependent on what the individual brings into the experience and expects to get out of it. An individual's respect, or lack therof, for a substance can most definitely have a tremendous effect on a their subjective psychedelic experience.
Welcome to The Nexus! I hope you find here what you are looking for, and then some!