not mentioning about gameplay but trying to have retail balance on acis gonna be a big problem. im 100% sure that the server gonna fail for this delusional idea. even in best scenario, if everything goes well, l2 itself designed without mana potions and limited buff times. so in general; with full buffs and unlimited mana potions, most of the classes will be over powered e.g duelist, grand khavatari. imagine a tyrant/glad goes aoe fight in full retail balance. a single glad can take over a party without its cp been decreased. there was a reason that those classes being nerfed in servers where you have access on mana potions and full buffs. not even talking about dagger classes' full retail formulas in l2j acis. you cant even compare l2off's and acis' movement system. that means in l2off, lets say in 5 seconds you can use 5 skills, in acis you can bypass the limit with its bad optimized movement system and possibly can spam 10 skills in that timeline. both, retail values and having to work on acis is a bad idea.