The luck thing is already there inside the game, from atma drop chance, gil dropped by monsters in dungeon, chance of getting excellent/good during crafting success, gathering HQ etc. If they really implement a number to show how much luck someone has, it's gonna get judged like ilvl and player skills, you'll probably be seeing messages like "LFM Primal EX fight, high luck or kick" or "this FC recruiting static members of XXX luck for better insta coil turn kill chance" or even "I don't want you to craft my item because your luck is too low, you'll get alot of Poor conditions on my 3star materials".

and I prefer achievements to be just achievement that gives out item reward rather than a luck point, as well as commendation becomes something that allows us to get exclusive items. If people achieve something solely on the reason to get more luck and not accomplishments, they'll become more aggressive in getting it asap and slams whoever becomes a burden to their 0.00001% luck boost.

Just my opinion, I'm not saying the luck idea was bad as it was used in other older mmo but I think the players would prefer something more constant and fair (like everyone gets to roll the 100-sided dice without influence from anything) and not from achievements, stat builds etc that will greatly change the way people play this game.