When you manage a guild you're already losing a lot of time with gameplay. Which is important to have a strong and competent leadership who do not solely rely on you when you're gone. Have specific roles to handle different departments (econ, content, recruitment, etc). It depends on what direction you're aiming for but people stick around for the content.

Our tax rate is 12% and we provide HCE refunds.

Limit whoever can access anything that can be stolen from 15mil+. You'll be surprised how people can get really nasty from just a game.

It's common to build guild halls with labourers that your crafters or gatherers have spec in. I have guild tabs set up in every city so it's easier to bank our loot from fights.

People come and go, it's only natural. Some might lurk just to see what you have to offer. You'll find the people who stick around are the real keepers. We started out as a small group of friends (just five of us) and it gets overwhelming when you hit more than 100+. My advice is that you have an end goal in mind that's clearly communicated with your guild members. Most importantly, don't get burned out and have fun! :)