When you want to play the questions, we are on the same page. Mythic Europe is full of mysteries. Some of the mysteries will be unravelled (and sometimes the players will be right, and be satisfied with being right).
My point was merely that there are too many questions to answer (play) them all. Therefore we do not worry with the ones we do not have time to play.
I would ask the question the other way around: In which chronicles would these events have appeared? Assume that we have battling dragons, giants and magi for a few years in Mythic Europe: which changes these would have left in history?
It looks like we have very few European or Arabic historical records of the results of the massive eruption of the Samalas in 1257, which was certainly worse than Eighteen Hundred and Froze To Death.
Untimely killing historical persons, burning down towns, meddling with battle results would change history. But magi and monsters battling it out in the wilderness or getting their abodes destroyed might leave as little traces in history as the eruption of the Samalas.
A few hundred wizards running around killing each other across all of Europe isn't a noteworthy event. Especially when both sides have Parma, so low level spells with lots of Penetration is better than huge flashy spells that level forests.
So this is basically the scale of a few hundred people with firearms skirmishing across the entirety of Europe. It's a gang war taking place mostly far from civilization. Armies of the dead might be horrifying, but how much more horrifying is that than an army of Norsemen going around raping, looting and pillaging (or just the neighboring kingdom trying to conquer your region)?
Well, not armies, just parties of Norsemen got enough attention to become source of legends and myths that had lasted a thousand years, but hundreds of magi battling to death, including a hundred flambeau with all their fireworks, went unnoticed?
The use of low level spells to come across Parma is something we deduce for the way the rules work, after doing some math. That's something we players know, not something characters have to know. I tend to think that the low level spell strategy is quite a modern strategy in hermetic terms. Otherwise how could House Flambeau not have an Intangible Tunnel fighting school yet?
These 'parties' had their skalds praising, of the embittered monks deploring, their deeds. While accounts of the deeds during the war against Davanallus or the schism war are locked up in covenants, and not even shown to all sodales.
While it is not the Schism War, here is an example of Magi affecting History in front of mundanes.
Consider that the historical record has plenty of magical events being reported and believed by the church and nobles in the real history of our world. In Mythic Europe these events actually happen, but that will not change the world much as mundanes already believed that these mythic events were happening.
There was an interesting series called the Medieval mind on BBC4 earlier this year, which is probably avialble on the BBC Iplayer depending where you live which looked at the medieval world view by examining chronicles and records of the time.
Worth a look to see how the real world viewed demonic, faerie and angelic events
"Master, why do you not use your magic to rule over the mortal realms?"
"... I treat with dragons and Faerie Queens. Why would I want to rule over illiterate mortals?"
because dragons need meat and faerie queens want vitality?
There are easier, less time consuming solutions.
depends on your style of reign. Humans can largely govern themselves once they acknowledge your authority, and there will always be criminals you can feed to dragons.
being 'fed' to the faerie queen would likely be perceived as a reward...
I like to answer this with the inverse: Without magi we would not have the history we have. Behind many of Original Timeline events there are Hermetic Magi, Hedge Magi, Faeries, Demons and Angels whose actions changed the course of history to what it is today.
Without their interference, history would have gone a different course altogether. i.e. "Without the interference of the Order of Solomon, The 5th Crusade would have led to the conquest of Egypt."
Did someone break the Lunar Limit?
Couple of thoughts on this.
The Order started really small, justa dozen odd people. It expanded but even at its peak in 1220 its only about 800 people spread across all of Europe and as far afield as Russia and the Middle East.
Most magi are scholarly and spend most of their time in the lab. They don't get out much because by and large, they don't need to.
Most magi have no need for power amongst mortals after their immediate need for servants is met. Sure, you could always use a little more coin to spend on a fancy lab, but once you have the fancy lab and fancy ingredients, what use is more cash?
Wars between magical groups are devastating for those involved but usually play out in magical regions which by definition are usually far from other people. Even if you call fire from the sky and burn a square mile of forest, if theres no one around, who notices?
Unless something is witnessed by literate people who write it down, did it even happen? The Vikings remember loved to sack monasteries because there was often portable wealth there. And who can read and write? Monks. So the viking raids get written about. They get passed down to following generations. And that writing isn't all scholarly balanced critique. Its much more "The hairy devils came from the sea and murder all my brothers and stole all the gold" because the writer were eye witnesses. Later of course we get wholesale viking migrations, massive movements of people and conquest. This far outstrips anything the Order is supposed to have done.
the Order is noted to be a somewhat open secret amongst certain nobles and churchmen with a cautious "leave them alone and they will leave you alone" approach. No one wants to push anything because everyone knows that "Wizards are subtle and quick to anger" and if they aren't causing problems, why risk it.
Here we get into gamey stuff. We have been given a setting and parts of it (the code for instance) explain why the Order has remained hidden. But what we do with that setting is up to us. I think its a mistake if GMs try to enforce that lack of impact on society. Let your players break the setting if thats what they want to do. Don't make it easy of course, but don't come up with reasons why they can't. Hard struggles make for satisfying games. If the players want to carve out a magocracy in the Novgorod Tribunal, then by all means let them. Give them some noble enemies, some Order mages who are dead set against it. Maybe have them face opposition from the church and offers of support from demons, etc. That could be a great story. Maybe even play up the arrival of the Mongols to give them a motive to createa magocracy, so that they can stand against those steppe nomad monsters!
Also keep in mind that this is not white wolf where everything is a prelude to the world of darkness. If there are some changes in your setting, make the changes. Try to keep them small for the sake of your own sanity, but if you decide that in your world the crusaders won the second crusade due to the participation of 3 flambeau brothers, that is fine, but keep the win small enough that you don't have to rewrite the 3rd through 6th crusades (or at least not the 3rd and 4th)
I just wanted bananas, tobacco, tea, bok choi and a discussion point. 
I'm sort of kidding, however, the lack of serious exploration by the Order surprises me. I would think some enterprising magi would want to explore, trying to find new vis and new knowledge.
If North and South America in our world is the same in mythic Europe, you'd think there'd be crazy vis there. It is also out of easy reach of the order. The ability to control weather, conjure food, etc. Magic makes new world travel trivial.
If I ever run a campaign, I'll have Diedne running off to North America to rebuild. Instead of Europe colonising the Americas, a vengeful Diedne, after consolidating America in to the Cree Nation, colonises Europe.
the thing is that America for Mythic Europe is assuredly not the America of our world. Different physics to begin with. By Art and Acadame where we have North America there is the possibility that it is occupied by Arcadia (not a version care for) and by any account there is a bad of perpetual storms separating the Eastern and Western Hemispheres.
Of course the canon idea about what are in North America ignore the Viking exploration of "Vinland' as they called the new world, and to me the easiest way to get to the new world would be to find some arcane connection that was fixed during the Viking age, then leap of the homecoming- if the bands do not prevent this the way some regios do.
Voicing something as "an intriguing possibility" (A&A p.27 box) doesn't make it a canon idea.
The meridian devil, however, is canon...
