There's something I find interesting there, which reminds me of D&D.
See, in D&D, all the gods are objectively real. They show up, they do stuff. Not a single character in that world believes they don't exist. Religion in that world is not about which belief is true, but about which one of the different powerful things do I follow (and the question of what makes a god a God rather than a very powerful but mundane being is left muddy).
Westeros so far has shown 2 religions, an "old one" and a "new one"; and Essos has given us "the one true god". Now, the Old Religion worships the Children of the Forest and those old wise trees, which are objectively true, and the new religion seems pretty content to acknowledge that. We haven't seen objective proof of the Seven Gods' existence, but Davos' survival at Black Water strongly hinted of the Drowned God's favor.
So I don't think it's that bizarre. We're just seeing a world where very powerful and old... things... are objectively true, and whether or not they are Gods in any "true" sense of the word, they are worshiped as such.
I've heard it, too. I don't know if it's true, but Tyrion is a beloved enough character I surely wouldn't mind seeing him riding a friggin' dragon.
Also, one of the three dragons might be killed, so only the two Targaryens would ride. I mean, Dany has (*sigh* again) shown her lack of tactics when the first arrow (spear?) passed by her and Drogon, and instead of dodging the second she dived straight into it. I didn't expect the writers to kill a dragon on the first shot, but seeing that I thought, "yeah, it's gone".