So I have been thinking lately on how the devs could add something to strongholds that would give an incentive for players to see out guilds and to give a reason for guild members to actually want to invest into their guild.
So my suggestion is to add a new spot on the map that will allow you to build a AD (Astral Diamond) Mine or Refinery (something along these lines). It's a one time build and it's the only thing that can be built there, so it won't conflict with the current system. Once built, it would allow members of your guild to refine an additional 1,000 AD per Guild Rank. So if your guild is rank 20, you can get an additional 20k AD a day. The catch is, you have to go the npc at the location and ask him to do it for you. This gives a good reason for players to seek out, specially new players, and join a guild. It also gives an additional incentive for guild members to work towards helping out and improving the guild.
Now, I have spoken to a lot of people about this ideal and the general thought is that 1k-20k a day isn't enough, but I understand that if this amount is too high then the devs aren't going to do it. Maybe the devs can figure out a balance, but I think 1k-20k extra a day is a step in the right direction.