Re mass deleting --
In FTM 2010 (not sure about earlier versions)you can delte multipe people at one time. Backup up your tree first. Select a person at the bottom of a tree. Go to Publish. Select charts. Select Pedigree Charts. In the chart options section adjust the number of generations so that you are including everyone in the tree. (You can select a high number to be sure - if you select too high a number, FTM tells you did). Click on the chart. Right Click. You should see an option "Delete From File". Click on it. You should see an option "All persons in the Chart". Click on it, and you will delete everyone in the chart. This can work in reverse too, be selecting a Descendant Chart. I suggest compressing your file after doing mass deletes.
Jim Vincent