A nit with 3). These matters have been pretty well dissected (even) here, across the eons. The 'scientific method' obv cannot apply to metaphysical ponderings, you might concede (?) Nope, no testing, experiment by peers, Michelson-Morley speed-of-Dark to 6 significant figures, etc.
And nobody will get anywhere.. attempting to find language to 'prove' that the idea even, of meta?physics is either necessary or, ahem realizable -- given the sordid state of most frantic Jelloware in the Age of transistorized speeding-up and time-filling to neural overload.
Given all the grounds for cynicism re most homo-sap mutterings, ratified daily by capitalism / the actual extant US religion - I'd assert that one can simply elide the corporate theologies and 'religions', investigate for oneself; exactly as all the memorable ancient Honchos did their foraging. What's to lose?
Then.. if you Find Something umm transcendental? Keep it to Yourself! or some idiot will start YAN New Religion and today, prolly with a \ufffd. (We never hear from/about the quiet ones, who just smile a lot. Love. It.)
Carrion