class change is not p2w also and you can attract even more players,nowadays people are avoiding these kind of servers where they have to make the quests because it is what it is,quests are annoying. Adena is x2 while xp is x3 so adding an option to change it for adena is helping the players but with the current situation you force them to make them. Instead of giving people the options make the quests or don't join you can give them: make the quests or buy them so adding it for adena+donation isnt p2w but a win-win so think about it
and " project is based on oldstyle gameplay" is not a good option for l2 players in 2020, they want to play the game and not to waste time doing quests
"everyone need to make your quests, it takes some hours only" - indeed but its some hours / char, so that means if you want to make your own crafter,spoiler,buffers,summoners,destroyers you will waste days and this automatically cuts your will to play ;)