Editing After Effects's Adobe After Effects 11.0-x64 Prefs.txt file will solve your problems in CS6 easily.
That file can be found in C://Users/username/AppData/Roaming/Adobe/After Effects/11.0
Change the value "Import Options Default Sequence FPS" = "30.000000"
to "Import Options Default Sequence FPS" = "25.000000"
Presto!
Then ,when importing a sequence of images, click on the first one only, optionally tick 'alphabetically', AE automatically imports all images into one sequence @ 25fps.