I try and do what you do early in game. I try and use charcoal for everything and save my coal. Later on, I use coal for when it is preferred. I got a silk-touch, repair II, pickaxe as well as now a fortune III, repair I pickaxe, and now have essentially unlimited coal. I have over 1k coal ore blocks to be turned into thorium or fortune III'd for moar coal. I don't really use coal coke all that much, as charcoal can be used in place of it, and coal is much more valuable for use as coal dust with various parts of GT.
I cringe myself when I resort to using it, but for all practical purposes though, it doesn't really matter. I do bring a stack of wood, and make more torches with it as necessary while mining. I've gotten so much wood from my small SC tree farm, that I've had my farm turned off for a RL week, and still haven't gone through all the wood and charcoal I have, although I am starting to run a little low on saplings.