My suggestion is an obvious one. We need to be able to transfer our character to another server. It might be difficult to arrange if you've not planned for it but users need it and company needs it.

Why players need it?
I can't even remember choosing a server. I've put in hours daily into this game and lots of money too. I played months in a seemingly empty server with all events either during my work hours or can't get friends to participate with me. I now realize I've been playing in the wrong time zone and probably an empty server, losing most of the game content. This is devastating after I'm this invested in my character. I can't just start over now, but there's nothing I can currently do except quit or keep playing the game in solo mode and without most of the events.

Why company needs it?
I'm sure a lot of other players are quitting too when they realize they don't get most of the content and feel alone. People, me included, would be willing to pay for this service, generating direct revenue, but also keep generating it after they can once again enjoy the game. The more people have invested in the game so far, the bigger the chance they will quit once they realize the situation and therefore it's more likely the whales generating revenue you are losing by not offering this service.

This can't be an impossible suggestion, many other games provide it for a fee. Think of it as an investment if player happiness is not enough