>>2418959The bullet Tsumugu had would have been pointless. It was only viable when Ryūko and Senketsu were still gaining power during the tournament. Once Nui showed up and Ryūko went to monster form, any life fiber enemy encountered after that would have been too powerful for the bullet to stop them. So it was abandoned.
The only real plot hole I can think of right now was the failure to give Junketsu a final form as hinted at during the OP2. Everything else was either failure to capitalize on potential or people getting mad things they speculated didn't happen.
