NX1000: why not?

The forum ate my first attempt to post this, trying again and probably leaving something out...

I'm considering an NX1000. Just got an RX100 and love it. When I got the RX100, I considered the NEX-3N and E-PM2 but went with the RX100 because the low light performance was better without spending more on additional lenses. Problem is, the RX100 has only whetted my appetite for something more and I'm still considering a CSC.

The biggest draw back of the NEX-3N (currently $450) for me is the UI. I really hate the menu diving. I've heard similar complaints about the E-PM2 and E-PL5, but haven't had the chance to play with one in person as no store in my area carries them.

The NX1000, on the other hand, has an excellent UI. Probably the best UI of any CSC or compact I've ever used, at least for how I interact with a camera. Between this and the low price of the NX1000 kit ($330-345 on Amazon lately), I've been tempted to get one.

Possibly salient points:

1. I take photos of kids in low light, landscapes, and telescope-less astrophotography. I'd like to do more starscapes, star trails, etc while backpacking and camping.
2. Built-in flash is always nice, but I rarely use it- flash was only used on the 13 of the 1960 photos I've taken on my RX100 so far.
3. Exceedingly unlikely I'll ever spend over $500 on a lens, so any benefits of the NEX or m43 systems gained from the high end lenses isn't really relevant to me.
4. I'm mostly JPEG, but willing to work in RAW if the gains are significant.
5. Don't anticipate buying any macro or telephoto lenses.
6. I see myself buying fast prime or two, in the areas of 24-28 mm eq and 45-70 mm eq.
7. Want a remote for time lapse and bulb - this seems to exist for the NX1000.

My concerns about the NX1000:

1. Low light performance: no DxO numbers and the NX1000 doesn't seem to be included on various standardized comparison shots. I imagine the NEX-3N does better at high ISO, but what about the NX1000 vs the E-PM2 and E-PL5?
2. General IQ and DR: again, no DxO numbers. Not definitive, but does seem to help as a guide.
3. AF: AF speed in good light seems good in fw 1.11 (compared 1.11 and 1.01 side by side at Best Buy), but what about low light (stars, kids)?
4. Does the NX system have a future? Adoption seems low and while they might be playing the long game,  I figure it can't hurt to ask.

One of my measures for how a camera might do for the astrophotography is looking for a shot of the Milky Way or some cool long exposures of the night sky. I've not been able to find anything so far for the NX1000 - any leads would be appreciated.

So- talk me out of this! Or into it. What am I missing?