I really like the idea of a tax to other guilds, I just wonder whether it penalizes the smaller guilds, who possibly recruit more than those established guilds that close books on recruitment quite often. The penalty of no recruitment wouldn't matter to them.
What about a fee to enter the KRs associated with the area of sabuk only.. NPC taxman at the door to ZT, MK, FB, LDC? Those guilds that kill lots of bosses (i.e. the bigger, richer ones) get taxed the most)