Rhythm - I think that your questions are partly meaningless, and I don't know what's your real agenda.
When you ask "how do I come to my conclusions" it is like asking a person how he thinks with respect to "cause-and-effect" relationships. I have a certain way of personally solving the issue of "cause-and-effect" relationships by using a multiplicity of scientific principles eg. Humean logic relating to contiguous events in the absence of confounding variables, Popperian experimental testing procedures that rigorously test a theory for its falsifiability quotient, Haackian criteria relating to concordance between different theories in a particular field of science (web of belief ideology).