You will love going from 5.5 to 7. The bigger changes happened between 5.5 and 6 (or so I think). I am glad they added the zoom and hand tool to liquify. The also moved liquify and extract to filter menu (which makes more sense). When using filters, there are some that you will see change on your image with preview checked and others you will see only in the filter dialog window. As for key combos ... I remember a few that I use on regular basis but those I use less often go right out of my head. Mostly the Tab and Shift Tab toggle and of course the space bar temporarily changes tool you are using to the hand tool. I hate using the navigator or switching to hand tool and going back to tool I was using.