Now that gold has become a much more valuable resource I can see the very real possibility of guild contributions decreasing significantly while players concentrate on the new kingdom leveling system. Why don’t you design a “Tithe” feature for Guilds where members will have a percentage of gold automatically given to their guild whenever gold is earned?
The Guildmaster could set the rate (default 10% of earnings perhaps) and as guild members play and earn money their percentage of the profits is put into a Tithe Fund. Higher ranked members (default Commander and above) can use that gold to pay for tasks. As always, members can add above and beyond to the guild and use their own extra gold towards the Tasks they wish.
I can see this being a great Guild Solution now that players will want to use more gold for themselves now. I can even see different guilds setting different Tithe rates: so you want to join my top-ten guild? Everyone needs to fork over 40% for the privilege!