yep, grocery store requires a full revamp with some updates to prices, daily renewal amount and also to the items available there (adding stamina potions (normal), myoboku grasps and cultivat scrolls wouldn't be a bad idea).

hopefully they'll put even training pots in it :D

yes

When it comes to Moon/Sun shop, i would like to add the idea of increasing the cap of the Moons and Sun maybe, increase the restock amount of some items too like Cave Keys ..

Lets say that if the goal daiske claimed was to make cave keys more available it failed for the simple reason that both in monthly event and in spece time bet chip shop there are better options to choose among so none sane of mind would go for cave keys there.

One way to reach that goal is the one you and garv said, another one would be to actually add cave keys in swb as additional rewards inversely scaled to the ranking (so top 3 do not get them, top 10 that aren't top 3 get 5/10 and who is not top10 get 15/20) or they could change how the land of wind desert feature (forgot the name now) works to actually grant 50 keys minimum to whoever take part in it.