looking at your posted images, it does not just seem to be a bias to mauve on the RH one, but as you say, a lack of definition in a range of tones, those belts of trees in mid pic. It looks like the sort of thing one gets if one's elbow gets jogged when trying to do a very fine adjustment on a curve - but this should not apply to an image once converted to tif or jpg.

I don't know what print preview ('soft proof' in NX) quality you get on the progs you are printing from, but may save a bit of ink and paper if there is a 'true reading' one and if you can toggle between proof on/off it may help find a set of settings where there is no visible difference or at least eliminate a few where there obviously is.

Lastly if your epson 2100 driver is of similar vintage to my old 1290 one, in the dialogues immediately before printing, it was essential to turn colour management to 'no change', every time, ie leaving the host software to do it and disable those C,M,Y, contrast & brightness sliders.