I ditched all my max revives/potions save 40 of each and I haven't had any problems.
I hang on to 600 Golden Razz Berries which takes up a lot of space.
Usually hang on to about 50 Rare Candies but I've been trying to use lots of them up.
I don't think you need 200 max potions/revives. Even when taking down gyms you can spin more every 5 minutes, and in emergency you can switch to disposable mons (e.g. high level eeveelutions/Arcanines) or spare Raid Boss captures, then restore them in times of plenty. Whenever healing is sparse consider using bulky generalists such as Lugia.