You seem to know that this is not something you can expect help with. Once those systems are in place Blizzard does not get involved. It is a matter of player responsibility, as you said. The GMs are not allowed to refund tokens outside the in-game system that has been created.
They used to do more, but as usual, people abused it. They would get gear for one purpose, use it for that, then want to switch it out for raid or something. It drove up ticket times as you might imagine. Blizz changed the game to ensure it is harder to make mistakes, that players have a refund option for a set period of time, etc. Players in the end have to have some responsibility.
GMs would love to help - but honestly they are not allowed to fix every little thing a player wants. You are right, there is not much they do in-game anymore. Not that they ever really did.
- Char unstuck has a self help tool but if that does not work the GMs WILL move you. Some cases require that, but they want the tool used first so people don’t sit in a queue if they don’t have to.
- There is a self help tool to un-delete characters now.
- There is a self help tool to restore items now - and it sees what the GMs see.
- There is a self help tool to get back lost mail in some cases. That one is super time sensitive.
They gave the GM tools to the players.
The rest of the things you said - no Blizz is not allowed to give game hints, they don’t get involved in civil disputes between players, and they don’t get involved in the free market AH.
This article on what GMs can (and can’t) do might be helpful.