I agree with your answers to 1 and 2, but I simply can't accept third. Dual mode is very useful and I, for one, use it most of the time and would like to switch to it regularly. Sometimes, I'd like to force phone to single mode and this app comes in handy. But when I would like to switch back to dual mode, it is still time consuming. I think that a lot of people use dual mode at least some of the time.

Another aspect is that all applets offer exactly the same function as options in "Settings", and in settings you can use Dual mode, which has proven to be very useful.

I don't want you to make app more time consuming. You could implement, for example, swipe gesture through the applet button to switch Dual mode on (or double tap or holding the tap for 3 seconds or...), which wouldn't make app more time consuming since 2G/3G switch uses single tap.