1. If you set it up so that your druid's key press from that is done via a separate Mapped Key using a Do Mapped Key Action, you can toggle that separate Mapped Key with a Mapped Key State Action. Unloading it with such an action will mean Do Mapped Key cannot do it.

I've done something similar for my 5 paladins, where I can set my ret paladins to switch between exorcism and flash of light for instant cast procs. I actually set it to rotate between healing themselves, healing the tank, and all-out DPS mode (my healer will also start dpsing).

2. This is in development