I've loved and used Commotion Pro for years for its simplicity and auto clone and auto paint features for rapidly frame by frame removing dirt and scratches. It isn't needed for Motion tracking, color correction etc. which work better on other tools of course.
But i've now upgraded my Mac and have to find a new tool. Ive looked at Photoshop but it doesn't seem to have the simple auto paint/clone feature. Any advice on the best replacement?

try autodesk combustion2008 for osx(Apple® Mac OS® X 10.4.9 &PowerPC® and Intel® versions of Combustion) .It has great paint tools but i don't know how much "auto" you'll find them.
Some high end and expensive solutions would be pixelfarm pfclean , foundry forge....