djdisbro,
I've considered getting a NC2x, but there have been alot of question marks, your post is helpful.
However, for the task of controlling other keyboards/modules, most of your minuses are addressing its shortcomings as a keyboard with sounds in its own right.
To have 9 faders mappable to MIDI controls is not bad, certainly enough for many of us. As far as WASAPI, what issues are you having? For those of us that love having an audio interface that is built into the keyboard, this is of great interest. Thanks
I agree with you in that having 9 drawbars is great, but depending on your needs buttons to increment/decrement presets, toggle effects on/off, etc. might be desired.
As far as ASIO vs. WASAPI a lot of that will be determined by what your computer/software you are running.
Historically ASIO was the more stable up until more recent versions of Windows 10.