Personally, in the interest of harm reduction, I feel it would be irresponsible to call this mix anything but stupid. The doses may not be extremely high but, aside from tolerance, there are any number of environmental, physiological, or situational factors to consider before you can really deem something 'safe', as the answer will be different for each person. If we are going to consider ourselves educated about drugs, then we should recognize what is and what is not responsible usage, and I would consider this irresponsible. People who are too cavalier about their drug use are the ones who end up on the 9 o'clock news.