FrozenPhoenix

That honestly doesn't sound like good game design.

So, ran into a bug with the tutors that are located under the main hall. Tutor that teaches the elemental punches and such would not teach my Weavile Ice Punch. Not sure of any other moves that aren't working(if any) and not sure if I had gone to the actual tutor at his stand in Peridot if it would have worked(at least in the Sandbox, it taught it properly in the base game).

Hidden Power requires specific IVs for typings. Special Attacking Pokemon also generally benefit from 0 IVs in Attack as this means they'll take less damage if they get confused(while still maintaining the heavy damage output as their damage is based off their SpA stat). Also if someone wants to create a team to abuse Trick Room, they generally want their Pokemon to have 0 Speed IVs so they're faster under Trick Room.

No, she wants a Sandshrew. So you have to catch Slash and breed.

So I believe there's still a bug around Keta and Amethyst Cave. For me he was kept triggering after I saw him the first time, whenever I stepped on the activation tiles, no matter where in the line I was. Ex. When I was first told to go get the Soul Stone, I went back through the Cave, and triggered him again as I headed away from the Village(and thus when I got to the red stone, triggered nothing). Can work around it by taking only the truck/taxi service to and going through the front entrance of Amethyst Cave(and leaving through it after you're done there, and taking the truck/taxi back to the Village), but if you step on the tile, especially after getting the Soul Stone/Doing the event in the cave with the Stone, it seems to lock you. EDIT: Also, as I managed to workaround above, found an NPC who keeps you stuck after defeating Keta if you talk to them. Screenshot here