I use one tone curve, Lab-L, along with the Exposure and Black sliders. Haven’t noticed colors going wacko. Color adjustments I do with Lab-b and -a, the HSV equalizer, and occasionally Lab CL and CC. I’m fortunate enough to have a wide-gamut monitor that shows most of Adobe RGB, and I use Adobe RGB as my RT working color space.
Since RT is after all a raw developer, I export an Adobe RGB .tif and finish in Picture Window Pro. PWP has a good color-managing print system based on the lcms engine.
Are there flaws in my minimalist procedure?
For examples, converted in PWP to sRGB for the Web, see images tagged Raw Therapee at