I think it's rather annoying that only christians can go through other's demense without being at war with them. Going past the fact that it's rather intolerant of PI to do that, it's very bad in gameplay reasoning. For example, I'm playing Tripoli right now, and I see a independent sheikhdom that's not at war with anyone. If I could get it, I could get a new title. However, I can't, as the Emirate of Damascus is in between, and I'm not a christian. It is COMPLETELY impossible for me to ask the ruler of permission for going across his lands or even just ignoring the ruler and going across. It seems that Paradox didn't plan for this. If you're going to take away the ability for non-christians to move across other's lands without asking, at LEAST add an option to ask for military access. If you're surrounded by blobs as a non-christian, it's almost impossible to conquer anything, meaning that you're most probably doomed.