Sounds like you have a passion for Warhammer and the stories it inspires.
In this situation, you need to focus on what is possible - not impossible. Using Warhammer name, characters, events, designs etc - thats impossible from a practical point of view. Producing a full-blown AAA 3D title is also impossible from a practical point of view. However, what IS possible is taking your basic idea of "consequences" and development of the player character, and the party that follows them and applying that to a simplified 2D game with a "universe" of your design.
What is also worth considering - and strongly advised - is taking a look at how a games series develop with each game. You might not be able to apply all of your ideas in the early entries but thats fine as it leaves a challenge for the games to come...
Look at the games of id software. Doom took the world by storm, but it was only possible by id making Wolfenstein3D first. And Wolf3D itself was only possible with the Catacomb games and even then, further back, a game about a tank rescuing civilians from monsters(I think? Pretty sure it was)...
To get around the issue of inspiration of Warhammer - look at the development of the game itself. Its just the classic game of historically-based war games - played by real-life generals - given a sci-fi setting. Hell, most of Warhammer 40K was a rip-off of ALIENS, Starship Troopers etc and thrown in with the usual Tolkien-stuff like Orcs, Elves, Undead etc...
If you have little interest in programming, but willing to put in a bit of hard-graft, then maybe look at either Unity or Gamemaker to at least knock together a "taster". It will take a lot of hard graft, but with such packages - especially Gamemaker - you could knock out a 2D version of your vision. Set aside the next two or three years and you'll probably accomplish that goal. Just, move away from Warhammer, but keep that warm feeling it gives you.
Anyway, good luck!
