I have to confess, trying to reconcile self-contradicting canon is one of my favorite things to do in a fic, or to see another writer do well. It's a fun challenge to take weird errors, or gaps in logic, or things that seem incompatible on their face, and actually make it work. Also stories that try to come up with reasonable explanations for game mechanics.

Not so much romance in 40K, I suppose. ;) Although I bet that doesn't stop some fan writers from trying! Rule 34 and all. But yes, all kidding aside, I totally agree with you that romance in all its forms is an excellent way to get into a character's head, or bring out interesting character interactions.