KangaRube here:
1
"Surprising"... hum... To give one particular thing, something that actually surprised me is finding out through researching for Khenbish that apparently there is a really big opera culture in Mongolia. In the Soviet era, the Soviets just kind of thought "oh, you guys already have a culture of mannered singing to be heard over great distances... we'll build opera houses here." And it took off in popularity, with the Ulaanbaatar opera house putting on both the usual repertoire, but also some major Mongolian operas, based on their own history/stories/mythology. It was just something that made me go "Huh? What?"
Perhaps more significantly, there is something that I am not sure exactly how to articulate--- something like that the ancient sources from which we draw really are "that good", that modernized retellings (even good modernizations that are worthwhile in themselves) never really hold a candle to the depth of passion and vision in those ancient originals; they are more often than not more complex and more accessible than one might at first think. "We are merely standing on the shoulders of giants", etc. That is why I have said a few times that if Minotaur Hotel inspires some people to pick up a few translations of Sappho, a copy of Homer's Iliad, Hesiod's Theogony, etc--- that would be Mission Accomplished to me. Haha.
2
Probably Greta? Some people sort of honing in on her and making fanart or memes of her, even if it is just for the lulz, still makes me chortle. But most of all, I just find it kind of sweet that it seems everybody is somebody's favourite.
3
Regarding the third question, a long while back, I actually had thought about this in the context of opera, and thought of a few singers for various characters. For Asterion, I assigned the basso John Tomlinson. Here is a good example in English of his singing, the first bit of "Wondrous Machine" by Henry Purcell at 5:03 of this video:
(although a guy speaks over some of it and it fades out. For some reason the video of JUST his performance is no longer available on youtube(?!?!?!), so this will have to do for now...)
Tomlinson just has a great warmth and sensitivity, as well as dramatic intensity; he even also has experience playing a minotaur in the Harrison Birtwistle opera.
With the help of a time machine, too, I would probably cast someone like tenor Franco Corelli as Luke--- just this big brash pushy kind of voice.
... Or maybe Ramon Vinay, a personal favourite tenor, who is more dark/dramatic. Or maybe Vinay would be a better Pedro (who also should be a tenor).
As for the others, I only thought so far as voicetypes. Argos would also be a tenor. Kota, Storm, and Khenbish probably baritones. Themba is another bass. And the cobalts all altos/countertenors. Greta a coloratura soprano, of course (Reri Grist, perhaps?). And maybe resurrect Maria Callas for Piedade, the Colonel's Widow.
I would kind of hope for something composed kind of chamber-opera-y, maybe invoking really early opera things to make it feel especially "ancient" in tone, combined with more modern elements. Employ 12-tone-rows for big scary moments, have a fair number of uncommon instruments to show the bringing together of various guys across the globe.