I have seen a very long delay in accessing both the Guild bank and the Guild store option on this banker and others. The mouse icon just spins as if it is trying to download data. Frankly I have yet to be able to access either as I simply don't want to wait on it.
I dont know but there should be guild store, I have seen that is enabled but there is no option to access it. I havent tried on other alliances or other locations