Hey there!
It's great to see someone besides me using this mini pc. I thought I was the last one!
I read you want to install to NAND, it seems not to be as easy as simply dd, because the boot files are different, even by using the cubieboard boot script I could not succeed. What finally worked for me, after searching a lot, was to use prebuilt images from a different a10 system - pcduino and pcduino2. You get the image or kernel, start from that, and then replace the rootfs files with whatever you want. I am now running from Nand, although it's not anymore TC, just a regular debian or a very small custom rootfs.
As for the X setup I will try to remember, myself i'm not using X anymore, I think you had to load some extensions and then it would work, which extensions did you get?