I think the idea sounds great and you should begin! At the very least, just the challenge will stretch and strengthen and expand your own natural writing ability, so even your regular prose will flow out in a richer style.
I second The Catholic Crow's ideas regarding inspiration, especially City of Angels. Also, many antichrist theories suggest that demons will appear as normal humans (not sure about angels). In Bless the Child with Kim Basinger, a human child with heavenly powers battles humans with denomic...
You can experience some of your weaponry research first-hand at shooting ranges (guns and archery). Google one near you and find out what their suggestions are for beginners. and see if rentals vs. bringing your own is too expensive. Some ranges have occasional "sales" or Groupon type coupons...
The last two sentences of your quick description really drew me in. I like the bookmarks, also. Personally I prefer to get bookmarks than business cards because I actually use them and I don't get them as often. I'm inundated with other people's business cards and usually end up guiltily...
Follow current anthropology and archaeology websites. Now and then they unearth something that throws status-quo history and pre-history beliefs back to the drawing board.
I can't speak regarding the military, but have some thoughts on agriculture. Ancient societies on various continents created complex and prolific agricultural systems that were able to feed huge populations even on less than perfect land. Various reasons why those great systems eventually fell...
As a reader, I'd have to want to princess to be rescued to continue reading if I were convinced it was what the male lead wanted. As others have suggested, since we don't like her, hopefully there's another reason why we want her saved such as that she has exclusive knowledge important to many...
Hope I'm not too late to offer something. This link has numerous stories on Native American folklore and mythology of the Pacific Northwest USA tribes. Lushootseed Legends (Folklore, Myths, and Traditional Indian Stories)
In lists of famous shamans, many are simply called by the culture/region's term for shaman. Such as the name "Quam" described in Shaman Links: Quam — “The usual Turkish word for shaman.” A name meaning diviner. From: Animal and Shaman: Ancient Religions of Central Asia By Julian Baldick
Like La Volpe said, give him a tag as well. In one fantasy (have gone blank on the title) regarding a young woman who would be named later, she was simply called "the assassin" at first, because she had been trained as an assassin as we'd eventually find out.
Some real life experiences can be toned down to save time and money for those who don't have the budget yet. At least they create material for detail that can include all the senses. - An authentic Chinese restaurant owned by a Chinese family rather than traveling to China (no, not home...
I find myself always reading them, but feeling impatient if they're long. I want to jump right into the main story, and if I page through the prologue and see it's many pages long, I'll still read it, but with a slight twinge of wanting it to hurry up.
I would need the main character to also be confounded, and to know he or she is confounded by their actions. Otherwise, as a reader, I'd think I'd missed something or that my reading comprehension was becoming demented.
I love some of the basics (rags to riches; being lost then finding home again but in a better way than home was before; getting from powerless to powerful etc.) all being deliciously wrapped in a fantasy world I'd yearn to visit.
I love introspection in fiction. Of course it can be overdone and drag on like any other component of fiction, but in general, I like it as long as I'm still "shown" alot more than "told" via inner thoughts.