You do not need the cursor to hover over the feature tree, you just need the last click to had happen there (bringing the feature manager into focus).
1. click on the feature tree and use the arrow keys - you play with the features.
2. click on the rollback bar and use the arrow keys - you move in time
3. click on the graphic area and use the arrow keys - you rotate the viewport
Watch THIS VIDEO for more information in this regard
Have you tried using the Part Reviewer add-in? It's not a keyboard arrow key function but is a lot less finnicky than the rollback bar/arrow key method.
... and you can add comments per feature.
I thought the macro solution sounding perfect, but when I try to "run" it I get a
"run-time error '459'; Object or class does not support the set of events.
I have never been able to successfully use a macro though, so it might be something I have done.
As a side note if I get it figured out; is there a way to load a macro by default in every instance of solidworks?
I will also look into the reviewer as I am in 2012.