Suggestions, from best to worst:
If ';' were a synonym for enter, my pinky would have less work to do.
People with non-QWERTY layouts may want different bindings. If this
were really rolled out, I suppose that could be dealt with on a
preferences page.
I could use the number shortcuts more effectively if the results were
numbered. Perhaps it'd also help if '-' meant "go down five results";
then you could go down a result list keeping your fingers on the
number pad/row.