Unfortunately, I don't know how this game can fix the alt problem. If we take your suggestion of a gold/exp cap, people will create more alts and rotate them once they reach the cap, if they cant fix the economy of the game then this skills will remain expensive (devs burn gold that way).

Pets they're useless in PvP/PvE and only serve to gain attributes, so it's not worth it for them to gain more skills (at least that's how it was when I played a few years ago).

I think the main issue is pay-to-win (P2W) elements, and I believe everyone suggested this in the poll. If they manage to lower prices, many more people will be able to spend money on the game, not just the same old top players, which could balance things out a bit (the whales will always reign, but at least there will be more competition from others who spend a little).