When I am dangling from a rope some items get greyed out from my inventory, so I assumed the ones that didn't get greyed out could be used from the rope. However, when I selected the dynamite and pressed the fire key, I just disengaged the rope and fell to my death. Am I doing something wrong? Or is it not possible to use other weapons from the ninja rope in the first place?
LessPop_MoreFizz was right in that there is another keybind to drop weapons from a rope (or parachute/jetpack). The key is enter/return by default.