1. This is not my game, nor my company. The one who needs to do market research is Chris (and he seems to have done just that). That said, there is zero contention that whereas before 2012 we had a draught of 15 years and now we willhave 3-4 Firaxis(2k Games) products and 2 Xenonauts products in just 4-5 years. So yes, the market is clearly more saturated considering the X-com genre. Is it too much to land a success? That's not for me to answer, but for Chris (and Firaxis). And yes, making sequels is both avoiding risks as running into them as has been shown by the demise of the X-com franchise before.
2. I'm sure Chris loves the high fives, I certainly hope he also appreciates cautioning.
I think Xenonauts 2 will be quite a bit more dificult to land than Xenonauts 1 (especially if costs rise due to ambitious goals). I could very well be wrong, but I gave my reasons I see against it. Their importance/gravity is subjective (so yes, I could be utterly wrong), but they are very much based on facts.
So yes, I would love to see another game with a new plot. Primarily beause I have seen this plot too many times, secondary because there's a risk involved in rehashing the same game over and over again, especially on such short timeframe. And only Chris can answer if that's too risky or not (he seems certain it isn't).