Pictures looks really great. Of course it is easy to see that they are not finished and are lacking in many ways (due to unfinished things, not any other reason). I also like how You take inspiration from what You saw in past in movies or other computer games - everybody do that (take inspiration) if he is creating any form of art, but not everybody admit it openly and tell what his inspiration actually was. Also I must say that when I saw Marines Preperation 2, nearly in instant I thought about Alien 2. The first one brough my attention to Ghosts from Starcraft/Starcraft 2.
Howewer I am not writing this comment to just praise Your outstanding work. What led me to post a comment is really interesting question which You posted - how much players' emotions and way of thinking (and acting) in game may be influenced by non-essencial information? Because - let's face it - technicly what player should be interested is the final outcome, which is represented mostly (and in Starsector by far - completly) by pure numbers. In this situation some background pictures/illustrations are non-essencial addition, and logicaly ought to be ignored by player. Logically. But the truth is that people are not logicall in 100% (those who are, are simply not developing properly and need help in socializing and learning social rules). And that means Your plan has a chances to be succesfull. Because every person feels and sees world in very diffrent (yet at the same time surprisingly simmilar) way, an outcome may (and will be propably) diffrent in every situation. That is why I would like to encourage everybody to post some information, or even better - imformation supported by an example what You would need to see in order to make ilustratons/pictures influence Your decisions in game, DESPITE the fact that it is numerical data what You should be concerned.
Personally, for me showing that marines are not killing machines, but real people with faces is not the right thing to do in order to change my decision. I would be sending them on every occasion still - they knew what they are singin into. End of story - Full Stop. In the same time, I really do fell sad for maintance guy (the one which is suck into space) and his friend trying to help him, and watching helplesly as he dies in cold vacum os space. That picture could "help" me to avoid accidents, by not taking risks (which normally I usually take). Going back to marines and their loses during combat. In my case, I am sure that greater influence on emotions would have picture showing wife and childrens crying over their father corpse, than just showing "hey - remember, they are people, not machines". That effect could be improved by showing in a back other wifes and childrens greeting their family members returning from boarding action (concrast). But do not get me wrong, please. I am not saying that because I am feeling in that, not other way You should do that, not diffrent thing. Ok?
Also, I am sure that influencing only one of our senses (sight in case of illustrations) is not as succesfull as "attacking" two, three or all of them. What I would like to suggest, is to add some sound effect to them (sad music when showing casuality report and so). Using this simple "trick" You could actually greatly increase strengh of effects.
Ok, I better finish before I will write something strange or stupid