All I do is get Nikon's software to turn my files into Tiffs, and those go straight to Photoshop. Once there, I make a dupe which I label B/W along with the file number. From there, into Adjustments, and using the supplied route I do the conversion there and then, which also leaves the option of using the different colours to be used as faux "filters"' though in reality, these are seldom of any immense benefit, but now and again they make all the difference.
I see no point in going through all the hassle of first working one's ass off in colour: why? your eyes and mind already know what they want you to do - just do it. Colour, visible in the monitor, is more likely to mislead you as to your ultimate destination than not. Treat it as a distraction and dump it as soon as you can.
Basically, one has to have the courage of one's convictions; if one has none, the it's perhaps the wrong business or hobby in which to spend time. Without certainty there is no future.
How ironic that Photoshop, a tool that offers amazing possibilities, can also become your worst enemy if you over-complicate your life.