Hello,
I could say different things about the night lights but the main problem I encountered with my own experimentations in the past is that, at high resolutions, in approach/fly over/land, is the strong flickering they cause.
I was never really convinced, for that reason, of what I was doing. But it could be now easier, at least locally, with the new type of texturing .
It is not easy to soften this effect while keeping enough detail and even stay also with dxt1.
Currently, for some tests I did with the betas, the level 12 of your night textures sounds reasonable. It is, it seems to me, everywhere at a maximum level of 13 except perhaps - I forget - on Canaveral.