It's the only way in mono blue to deal burn damage whenever you draw a card , and you will be doing that a lot over the course of the game (especially once you hit max speed)
Update September 7, 2022: Promo card has been revealed
Yes, paying the dash cost for a creature counts as casting it, just for an alternate cost
Of course, the core MTG rules don't allow players to control each other's actions, but Mindslaver changes all that
Obviously just making new powerful cards regardless of that is something we do as well, but being a trading card game, it's always continuing from what came before. Sometimes, players surprise the card designers with how they use a certain card or deck, despite the dozens of hours spent testing and balancing them