I'm going to give this a go after reading your feedback. I'm sure that DH and I will like it, but I'm not so sure about the DDs
That said, they do like quinoa.
In answer or the soaking question, quinoa has a soapy coating which tastes foul if it isn't washed off before its cooked (possibly the reason the roasted quinoa tasted so bad??). This can be done just by rinsing thoroughly under the tap, or by soaking.
The overnight soaking is probably to 'increase' the nutritional value, as apparently it makes it easier to access and absorb the nutrition available. I think this is true of all grains? Perhaps someone could clarify whether I'm right in that, as I'm not sure.