CF is really the most intense mud i've seen, and the expertise is really high for the long time players. I know from experience, however, that one thing on everyone's mind when suspending disbelief is the fact that nobody poops. I know you've thought it too! "my character eats and drinks (constantly) and can starve to death, but what about pooping? C'mon zulg, why play at realism if you can't go the extra mile?"
Pk is a lot more interesting when outlanders cannot poop in a locking stall protected in the city. For one tick, every so often (depending how often you eat), your character has to find a restroom or quiet place. Then, if they are pk'd, well they should have thought twice about their pooping spot. In the cities there could be restrooms that serve all types, and have locking doors. Once your character does their business, they have better movement and feel refreshed. After all, if you're toting a log and running around the forest for days, I'm pretty sure you're unhappy and your morale should suffer. Rangers could have a skill to hold it, combined with their ability to go without food and drink for some time gives them an advantage.
If you get a warning "you really have to go!!" and ignore it, well, of course, things happen and you run around with a skunk like affect until you remove your pants or leggings. This could work like broken, and you pay someone to clean your drawers.
I feel this is the bit of realism that would really allow us to get into character. Basic necessities come first,and are part of survival. In fact, all mobs should also have pooping schedules, because they eat lots of adventurers. Making it realistic and having a really long line for the ladies' bathroom in galadon would be appropriate, too. All those crying girls and waitresses get in line. The reality would help people play more female characters too, because now they are seeing real life situations apply, like women taking forever in the bathroom.
My next idea is for menst.....