First off let me outline one important fact:
Guild Taxes only come out of coin picked up from corpses, They do not include: Quests, Items Sold, Auction Hall sales, or Gifted Gold in Tier 4 in a single group your likely to see 5 silver max on any corpse.
That being said, I have had my tithe at 100% for a week and so far I have donated a single gold to the family. Claiming a keep in tier 4 usually takes around 1 Gold per 5 Minutes. Hence my 1 full week of gold donations lasted a whole 5 minutes. For our family to claim keeps and hold territories, flip zones, and dominate we will need to increase our fund supply. I don't like taxing people and don't want people to think that the taxes come out of anything other than corpse gold. But without some serious increase to our funds, we wont be able to keep claiming keeps. With the na Anu getting closer to 14 the possibility of double keep claims is at our door step. I believe this would be the most impressive thing to see.
So with that what do you think our guild tax should be.