It may be possible to post some speech that presents phonetically inflected and in a glottal and nuanced cadence that mimics a real language but is in fact entirely false.
Yes - many actors do this when pretending to speak a foreign language (faux German, French, etc.)
Well, Paul's "tongues of angels" is pure hyperbole, but it would be relatively easy enough to determine if what is being uttered meets the universal criteria of "language"; i.e., whether or not it's simple non-cognitive non-language utterance or actual language.