You can't have more than two copies of a card in your deck
In addition to this, OP04-112-Yamato and OP04-104-sanji would also be important upgrades for this deck (and quite useful for the yellow color in general) and they are less expensive than the aforementioned, and you could start here
6 Rare Candy: League & Championship Cards (League Promo) $130.31 Sweet As Candy Without the context of the other expensive trainer promos, you'd be forgiven for mistaking this surprisingly valuable average-looking card for just another common
3 Hullbreaker Horror Hullbreaker Horror is one of the main win conditions for control decks
Yes, you can equip a tapped equipment
A lot of people love the game, but it's more the cards are collectible where Magic on the other side is so, so table-driven - a lot of people who play it are the collectors and there's really no in-between