While I'm wishlisting, here are the things Pokémon needs to do in order to win back my heart.
• Turn order should be recalculated mid-turn as needed. At minimum, turn order should be recalculated after mega evolution changes Pokémons' Speed stats and Abilities. Mega Beedrill and Mega Banette shouldn't have to run Protect in order to make sure they live through the first turn.
• Weather-changing Abilities (Drizzle, Drought, Sand Stream, Snow Warning) should last 2 turns instead of 5. Maybe 3 turns. It's just such an enormous boost, especially in Doubles. Like, there's absolutely no reason to ever use weather-changing moves over these abilities, and that really limits which Pokémon you can use on a weather-based team.
• There should be an Ability Tutor, which can teach your Pokémon any Ability it could have, including Hidden Abilities. Barring this, there should be fairly easy access to every Pokémon's Hidden Ability.