Remove internal edit mode and add "content" tool.
Make tools toggle-like by switching to last mode.
Enforce internal/external selection exclusivity.
Make MIDI regions translucent for internal tools.
Fix copy paste of MIDI and track automation.
Use color modifiers for dynamic region styles.
Restore snap when switching to/from internal.
Remove mouse mode toggling.
Move object tool to "grab" tool (key g).

Makes all tools under the left hand and eliminates the need for toggling.