I see you guys put a system that members can donate zeny to the guild.
My suggestion is that, if possible, you guys add a system that give utility to the guilds in game.
1 - With Zeny guild leader could buy temporary buffs for the guild members
Ex.: 1kk Zeny buy +15% HP 7 days buff, something like this
2 - Create something that worth have a dojo
I was one of the PARADISE leaders and we have dojo for a lot of time, but have one don't give anything to the guild members. Only one help in budokai, but nothing more. You guys could add something. Guild receive % of zeny spent in that dojo city, discount in NPCs from that city or guild can craft things inside the dojo to sell.
3 - Add a alliance system to the guilds, this way friendly guilds don't hit each other in scramble
This is my suggestion. Maybe someone already said them, but i don't see