So Drogon is taking Danaery’s body where and to do what? Bury it? Dump it in the ocean? A brief comment is made later that Drogon was last seen heading east. And??
Dragons hate the cold. He picked her up and flew east where it's warm. It's a long flight and he needed a snack along the way.
And why did Drogon destroy the iron throne? Did it actually know what it was? If yes, that implies human intelligence and emotions.
He was pissed that his master was dead and was just venting..the walls all crumbled nicely, but that damned metal thing didn't immediately fall apart, so a little more effort was needed. And very symbolic in a story telling way. It didn't roast Jon because he's a Targarian...so you can suspend disbelief that a flying, fire breathing dragon can perform DNA tests by scent, but not that?
But the theory is that dragons are pretty smart - maybe dolphin smart.
And where did that huge unsullied army come from? Didn’t at least half her army die fighting the White Walker army?
The Unsullied didn't bother me - they held their own and that wasn't that many dudes - maybe 1,500 out of 8,000. I'm more shocked that there were any Dothraki hanging around.
I'd guess Drogon takes here to Old Valyria. What I don't understand is, why is Bran going after him. What does he expect to do/achieve, once he finds him?!?! Might consider trying to warg into him, but well… Could even speculate that he warged into him to safe Jon and melted the throne, but that's a veeeeery far-fetched shot... Unsullied, most she ever had was 8000 + trainees. Might have lost ~1000 in here adventures in slavers bay. After the long night Grey Worm reported that about half of them were left, so maybe 3-4000. The Dothraki must have been a few hundred strong garrison of Dragonstone while the rest marched north. Not that I would seriously consider Dothraki to be the right choice to men the walls of a castle, but well, can't have been the ones that went north, no?!?! Question is where they are going now - Ser Davos should quickly build a new fleet to carry them back to the gras sea, before they get funny ideas...