Rythal, I'm not sure if this is the correct thread for suggestions, but I don't see a better one, and so here it is. Since you plan on use Ace3 to build the locales, options, etc, that allows LibStub and CallbackHandler. Taking it a step further, you could improve the Warehouse with syncing. To that end, would
LibGuildBankComm be of use to you? The API is easy and straightforward, the lib is secure, and only concerns itself with the guild bank. It also does most of the heavy lifting for you.