It seems that the number of abilities correlates with the rarity: uncommons have one, rares have two, and mythics have the full three
Not just decklists for these professional events, but also for regional championships around the world as well as lists pulled directly from MTG Arena
You can't remove oil counters from it if it's not on the battlefield, so you won't lose the game if it had only one oil counter on it before leaving the battlefield
A Birds of Paradise from that sheet went for 4+k, and considering there are some huge dragon collectors (including the gentleman who owns the Shichifukujin and a couple of his friends) around, Im certain the Shivan breaks 10k
Cards like Sanguine Bond and Starscape Cleric go right for the jugular without worrying about combat
You may move a Character to a Location on the same turn its played, and it doesnt matter if its exerted or not