I'm glad you like the plugin! :D
1. You can actually already change the Q of the filters - hold Ctrl (or Cmd on Mac) while dragging the points up and down to change it.
2. Good ideas! Similar things have been suggested before and it's definitely on the todo list.
3. There are plans to add a volume envelope on top of the waveform that you can freely edit, but it's an ambitious and relatively big feature which will take a bit of time to implement, but it's definitely something I want to have in the future.