clean the pots with a mixture of 1 part bleach to 10 parts water. Scrubb the pots out and rinse very well.
If the blight is bacterial that should take3 care of it. If it is viral it may not and nogthing other than using new pots would help in that case.
The blossom end rot is due to you watering process. Apparently the way you are watering is causing the calcium in the soil to seize and it is not properly absorbed by the plants. Try changing your watering habit. check the moisture in the soil near the plant in the morning. If it is dry two knuckles down or if the leaves are wilted (IN THE MORNING) water. Don't water from overhead-water from the base of the plant. If the leaves are wilted in the late afternoon that is as it should be and the leaves will perk up over night.
Blossom end rot will usually happen to the first flush of tomatoes and then get less frequent as the plant gets bigger. You can cut off the brown part and eat the rest.. Perfectly safe to do so.