I just installed Lockinfo, with it came Display Controller. When I uninstalled lockinfo display controller stayed. In cydia, u can remove libdisplaystack it'll take it out. (if u know ur not using software that needs it)
You can try. In the remove screen in Cydia if it lists any other thing besides the single one you are trying to remove, then don't remove it. As other things are still using it.
surely you have some use for "activator" (you can assign any actions to any commands)? i have set it up so that i never use the hardware buttons anymore (safe for turning it on)