You mention some valid points.
For example the potion problem is real. Most players have accumulated a huge amount of potions with no use case at all.

I personally also wonder if all these presales with all the hype and all the discounts for first-time buyers are ultimately counterproductive, because some whales might then make a huge splash, but everyone else may think after the presale that they missed out on the best opportunities anyway and thus see no point of buying under much worse conditions?
How about simply offering products for sale on date x for everyone at the same conditions and that's it. Without any presales at all?
A good product should be able to be sold continuously, without having to appeal to human greed (who gets as much as they can first?) in such an extreme way.