-More Quests, Possibly Daily
--Would add some extra flavor to the daily grind. "Defeat a (color) deck", "Accumulate (x) Quanta in a duel", "Win a game with your Oracle card still on the field", "Win a game using a Weapon", "Win with an elemental mastery (with/without X color)" etc.
-More Ways to gain rare cards
--Can factor in to the More Quests, and make it less frustrating for new players to get Weapons.
-More cards
--More variety means more potential deck types, meaning a more varied play experience.
-Less Arena Uniformity
--Can factor in with "More Quests" or "More Ways to Gain rare cards" by giving rewards for creating certain types of element decks or having the AI win a certain number of duels.
-Improved Spectate Feature
--Yes please.