DPX or Tif export for color correction on Nucoda system? They prefer DPX files but as far as I know it's not possible with MC. Do have Tif files the same quality? Have anyone experience with CC of Avid files on a Nucoda system?

No need to do either.  Nucoda can read Avid MXF, either 8-bit or 10-bit.  Consolidate your sequence, and send the Nucoda your MXF files.

But then I have at first to make a Mixdown of the video tracks and render all effects? Otherwise there is no order of the clips and the effects are missing or is there another option? With Tiff export is no problem. No render or mixdown.