The benefit of doing a Compassion/Lovingkindness wish as often as you can is that it opens your heart, keeps your motivation in the right direction. We have talked before about the direction; how can you make sure you don't lose it in your normal activities and everything else, do the Compassion/Lovingkindness wish regularly. Not just for the ants you might step on, but for people wherever you go. There is going to be another special mindfulness activity later for that, too. Wherever you are, in a bus, on a train, stopped at a stop light and you see people walking in front of your car, can you give them a little wish? Can you do it for your work mates, when you walk in to work, can you do it when you are reading the newspaper, when you read about any story, can you do it for them all, let us open our heart. Can you do it? Can you do it regularly? Can you do it for the people in Iraq right now, for the ones who are causing the problems and for the ones who are suffering from the problems? And all the different countries that are suffering from the same problems, can you open your heart regularly each time? Or, do you shut your eyes when you see the Iraq news, or the other types of news that are unpleasant?
So by doing the Compassion/Lovingkindness wish as often as you can and as regularly as you can, this will open your heart, it will keep your motivation and your direction in your practice in the right way.
The second part of the question, "I am wondering why the mental Dukkha comes before the physical?" I don't know that it always does, because if you break your arm and then you worry about it, we would say that your mental Dukkha comes after your physical. But a lot of mental Dukkha definitely comes before any physical Dukkha at all.