DISCUSSION:
I am not an expert in Star Wars or Warhammer40k, meaning I probably overlooked something or didn't consider its full ramifications, hence why I posted this on StarDestroyer.Net to get feedback and constructive criticism from people far more knowledge than myself. I enjoy the exchange of ideas, as it's what introduced me to the awesomeness of Warhammer40k in the first place.
MY TAKE:
I imagine the spread of the Force being the metaphysical equivalent of terraforming or panspermia with some similarities to the Borg’s assimilation process in that it incorporates previously-existing lifeforms into its energy field. However, it’s possible that there could be a high fatality rate as not all lifeforms will be compatible or that the dimension’s physics would try to reject the conversion.
If the Force did somehow gain a foothold in the cannon-W40K reality, my guess is that the Force would evolve into an intermediary layer between real-space and the Warp, perhaps symbolizing the balance of Order vs Chaos instead of Light vs Dark.
Possible impact:
- (1) The biggest long-term impact the Force would have is that it would make the C'tan plan to block off the Warp exponentially more difficult as all life would be indirectly connected to it instead of just sentient biological beings.
(2) The Warp and Waaagh! would become somewhat less volatile, meaning fewer Weirdboyz exploding their heads and a decrease in Warp storms.
(3)Sentient biological beings with little to no presence in the Warp, such as the Tau and Pariahs of the Culexus Temple, would experience a reduction in their resistance to Warp-based power and/or psychic-nullifying nature, as well as becoming vulnerable to the mutating effects of Chaos. A new tier in the Tau Empire’s caste system could emerge to accommodate Force-sensitive Tau for the sake of the Greater Good.
(4) Many psykers would need to spend months or years relearning control over their psychic powers, which would seriously hinder astropaths, navigators, farseers, daemonic activity, etc. On the positive side, the near-constant assault on the Emperor’s psychic presence in the Warp would temporarily wane. This reprieve would let the Emperor of Mankind catch his breath and slow down the gradual decline in his health and vitality.