Inventor's Axe doesn't enter the battlefield attached to a creature
after two instants and sorceries, you have four
By the next day, I was killing on turn three and the deck survived the loss of several other cards prior to a Pro Tour that was dominated by a combination of Grim Monolith and Tolarian Academy
The last set printed with a 1st edition stamp in Japanese is XY Evolutions / Expansion Pack 20th Anniversary [CP6]
No, a creature with regenerate will not be protected from exile
Mill never had the right support to dominate any format, and if the milling failed, the mill deck would be too far behind in the game and lose but in Commander, even with 99-card decks, mill might work with creatures like Bruvac, the Grandiloquent around