Just some comments, really its all off topic though
Are they part of the setting? Did "facts" of your story really happen? Yes you claim so, we all do. But the truth is you and your guildmates are the only signs of it being true. If so, is it?
Is what your saying by that (and correct me if I'm wrong) is that any guild who "creates" a history or background story that they do not rp out beforehand is invalid because the only background story is the one in the settings? If you think about it from a view that this world is "real" there are many things that happen without everyone in the world knowing about it. When I think about a guilds history (really refering to my own) I think about the unheard stories in the world, the ones that few know if any. No one, whether ncp or player, can say they have seen everything and know everything. Does this mean that every story is true? No and it doesn't mean each one exactly fits. Some stories are too big for them to go unnoticed but some are low key, easily able to happen without a great amount of people learning of it.
NPCs won't say a word about you. Places which are important in your story don't exist at all, or you claim so, that you own something what was never what you describe.
The current policy of things to go in PS is exactly like this and you really can't be sure this will ever change. We are mean't to have guildhouses in future, but this is valing only to guilds like fighters, mages, crafters and such (guilds exactly as they were in medieval times). 90% of current guilds are different, you all know the topic well.
Even the Vespers of Laanx, they don't belong there. Laanx already have its temple with NPCs inside, who know nothing about this "guild", None of these NPC will treat them any better than any other person.
All you can do is wait as the devs do the wole stuff for you, because you can't change the setting, make places story. While it is so needed for your guild, the setting is already written and it is obvious that if you want your guild to be IC, your guild story needs to go int setting. I'm not talking there about anything big, just some space in the world.
By making a character you are changing the setting as from this point there is e.g. new smith, noone may care about, yet it is part of the setting.
But you aren't allowed to do it with your guild.
As players we can never say whether or not NCP's will acknoledge our presence in the world for the fact that we can not control them. However, it can be assumed that NCP's (if you are treating them as actual people living in the "world") do notice us as well as our many guilds for the fact that we talk around them, talk to them (while questing), and do busniess with them (through buy/selling and training). Not saying you can say "This NCP is my friend" but they know we are here. Does this mean that "The Vespers of Laanx" will get noticed by NCP members of the church? Of course they will but their power over the church truely only can be limited to a more "volunteer" service less the NCP's allowed more (And I could be wrong). Also its very possible for many of the places people rp to have been to are real. There are places and things in the world even Laanx and Talad don't understand or haven't been too. The stone labyrinths are an example of a place and the portals from which different races came from as a thing. Am I saying one can have a huge city or kingdom as a place in their story? No, that would exceede the eventual limits of the land of Ylikuam but it can be assumed that there were smaller villages within the wild lands. For example I could, if granted enough people, start a village on the Oja Road ingame. Would it be recognized by the goverment of Yliakum? I doubt it because its small but truely its not possible for me to predict the actions of Yliakums goverment.
Arcane Order and their tower, i doubt it would happen (maybe they should be happy they are no more..)
Tower's could possibly happen because according to the website we will eventually be able to own our own castles in future developments.
Of course, his idea is doomed on IC failure
I disagree

. And I would not advise you saying that to other people attempting to make guilds, if you do of course you will have a problem with having rping guilds. Its always hard to get people to follow a guild with an extreme idea and more work but I think when one like that is established it makes the rping in the game much better than if someone was just to establish "another protect the people" guild.