How do I use different loops for each pattern within the same group?

You can do it all . Everything you asked in Video is possible but I assume you find your Workflow and which way is best for you. I would use Lock States but again depends on the Track I'm working on. Lock States can solve so many and make impossible possible. Mute Groups , Use Samplers to switch between them , resample as much you can because it's how Audio become more stable and using Lock States in Keyboard mode and placing them on linear Time Line in Pattern or Arranger is making so much possible with the simple solution. I wished you found solution.