I'm not quite sure what you mean by 'pink meat', nor what the problem with that might be, unless you're talking about the smokering. Pics and a fuller description of what you mean would help.
I've been using the Minion Method for all my cooks for many years and have not noticed any sort of bitterness. Perhaps that's a subjective difference. Though I almost never use Kingsford Blue (I do use the comp) I do use some smokewood for most cooks.
Those high temps would not make the meat tough. Meat is tough if it is undercooked, usually, and sometimes when overcooked, though in that case it is usually more stringy and dry than 'tough'.
Irrespective of cooktemp (I cook ribs routinely at 350-375), meat needs to cook till it is done, i.e., tender and juicy. The best way to determine this is to check the meat for tender; cooking for X amount of hours then removing the meat often does not work well. Checking for tender and cooking only to that point does.