A lot of this isn't so much "little details" as "please make suggestions of what things I should search for/poke at"
The hard, absolute difference between that world and this is the presence of magic--specifically, magical items of varying descriptions that are made from living people (the process kills them, it's generally done on those who were dying anyways for whatever reason), as well as a fraction of the population (probably in the neighborhood of 1%) who can both make such items, and recognize the general nature of any that exist.
The story will probably be set somewhere in the neighborhood of the Enlightenment or the early industrial revolution, in part because I didn't want to do Yet Another Vaguely Medieval Fantasy Story.
The main difference I wanted in terms of history is that, well, Christianity and Islam didn't become as ubiquitous. They're still pretty common--a plurality to a strong majority--in the areas where they were nigh unto universal in our own history, but--if nothing else, it's hard to convert by the sword or whatever when the guy you're trying to convert has a magic sword. It's usually not worth the trouble. So, most places have something a lot like the prevailing Roman attitude about religion--as long as you pay your taxes and don't hurt anyone, who or what you worship is pretty much your own damned business. Being a member of the "wrong" religion in this world is probably about like being an atheist today--you may get people who dislike you for it, and you may have trouble holding any kind of public office in some areas, but you generally will be left alone about it in your daily life.
Despite that, I'd like to have the same general arc if history. Roman empire, which fell apart from size, corruption, and barbarians, followed by a few centuries of superstition, not much technological advancement, and the usual sorts of barbarism. Eventually, probably starting from coastal trading areas and growing inward, science, learning, and the printing press bring about the Renaissance. At some point around now, Europeans start traveling places, rediscovering America (unless I tweak it so that the Vikings never left), eventually building empires, properly figuring out science, and starting the Industrial Revolution.
1. Do you think it's plausible for European history to have about the same "shape" even without the overwhelming influence from Christianity?
2. Any thoughts for specific little things that might plausibly be different between this world and our own at the same point in history? I'm thinking things like different (but recognizable) names for the nations/regions/cities/etc (a la my England/Saxony example), differences in national/empiric boundaries (for example, might Scotland still be a separate country?), and the like. Also, any that you think might be "attractive" to me but strike you as completely improbable would be good, so I know what to avoid. I don't want to throw my readers out of the story...
3. Any good sources you can recommend to get enough of an overview of the relevant bits of history that I don't do anything completely silly in constructing my alternate history, and/or my alternate 17th/18th century England?
As a side note, this isn't a "true" alternate history, since the point of departure is basically "There is this specific kind of magic, and it's been there since about as long as there have been humans". But I figured that, with the same physical geography and otherwise similar natural laws, etc, there might have been the same kinds of forces of history, et cetera, leading to a similar-ish world.
Think of this as a little like the Victorian-empire-with-werewolves in Soulless, or Europa-with-Sparks in the Girl Genius comics. Less "here is the point at which history diverged", more "here is a world a lot like our own, except..."
son of edit:
I think 1 has pretty much been covered (as per my comment currently at the bottom). Any thoughts on 2? Basically, I'm looking for alternate names, etc. that would make you go "Oh, she's talking about (place)", or "Oh, in this world, I guess (event) happened differently", but would not leave you thinking that this world is absolutely nothing like our own.