In the part about "What is Ars Majica" a part about a discussion on the game world and the boundaries to exist in the game amongst all players would be helpful. Some other games have done that kind of thing recently.
I am not a good enough writer to put together a proper piece, so I'll just write something which is setting the tone.
After the usual preamble about you play a character, blah, blah...
"Ars Majica is set in Mythic Europe. It is 1200AD in Europe where magic is real, and what some people consider myths and mistaken beliefs on science and alchemy are actually correct. We recommend before starting the game, have a discussion with the playing group about what they want in their mythic Europe.
The game world, like the real world, involves conflict. Horrible things can happen; torture, rape and when you add in magical elements such as mind control and shape shifting, the level of depravity can go beyond most people's imagining.
The world of medieval Europe has some quaint ideas such as rats spawning from grain and mischievous fairies souring milk. It also has some ideas that are distressing, such as disabled people being cursed by god.
Mythic Europe had a great distrust of strangers. Tribalism and racism is endemic. Due to the overpowering influence of the Christian church, anyone believing in something else; Paganism, Norse, Roman, Greek, Egyptian Gods, Animalism, Druidic, Wicca, Judaism, Islam, will at best be tolerated, but never trusted.
While many of those beliefs are on the fringes of Mythic Europe, they are true. A believer in Odin may get divine assistance, just as a Jew, Muslim or Christian might. The Druid or Wiccan could call on spirits and animals for assistance.The above are examples and in no way represent a complete or exhaustive list.
Sexism is not even a concept, as the place of men and women is so set in the fabric of society.
The story guide and players should discuss what elements they may want to veto in the game as the game is meant to be fun. While a character dying isn't much fun, it is a risk most people would accept in a game, become if the risk of death does not exist, success seems hollow. More depraved elements like rape, torture, being mind controlled to do both, players may want to veto, as it may completely ruin their game experience.
The playing group may decide their Mythic Europe is more tolerant of everything, different religions, different cultures, the differently abled, etc. They may decide women's liberation happened in 1000 AD.
The group may decide to set their game in Mythic Iran or Mythic Egypt. The group may decide the Abrahamic religions never rose to prominence in Mythic Europe, and Roman and Norse gods are the powerful divine influences. The group may decide to have the grittiest most authentic medieval experience possible.
The history and game world presented in this book is a starting point, and all playing groups should decide what parts of Mythic Europe they want, and what changes would make it the best game world for them.