currently (shaman 1.0.9) if I remove a package which other packages depend on, shaman will silently mark all the packages which depend on the package I'm using for removal. This can lead to unexpected results, such as (in my case), having your xserver removed and not noticing it until a couple days later when you reboot. This is clearly undesirable behavior. I think that when marking non-explicitly selected packages for removal (or even install), there should be a confirmation dialog showing the additional packages and asking whether the action is ok; this is the approach synaptic uses and it works well. I know there's an option in the final dialog before applying changes to see what you're doing, but it can be easy to miss one package in such a list and it is more-difficult to tell what triggered the undesired behavior.