Earlier quoted context omitted.
IMO we know too much (though obviously still too little) about PIE and not enough about non-PIE languages, and I find those much more interesting.
Yes, though it makes sense as majority of Europe and Europe-descended cultures are Indo-Europeans, with Indians and Iranians as the other major cultures. We know much about Proto-Semitic AND Proto-Afro-Asiatic, thankfully, due to the antiquity of recorded Semitic languages in the Near East. Proto-Austronesian seems to be clear too with the 600+ languages we have access to. Unfortunately the languages between the thre…
Vajda’s theory is still regarded as very tentative by the community, and even Vajda himself suggests in his most recent book on the subject that work towards proving a connection has barely begun. It is definitely not settled science.