For your last point, if you just continued to adapt 12tet music into other systems I think it would continue to sound strange? Not totally sure, you'd get used to it to some extent but I think it would always sound noticeably off esp if you were familiar with the piece in 12tet like we are with this one.

But there are entire music traditions using other tuning systems and they sound "normal" to the people who grew up with them. Notably the 24tet used in arabic music but there are literally dozens of others around the world.