It would be nice if one could chose if the UP/DOWN-arrows shall jump as many steps as in the EditStep-property and not just one row at a time as it is today.
I DISMISS YOUR IDEA!!! 
Just kidding, this is actually something I never thought I missed, but I tend to press either delete or the respective note/number printed in the pattern editor.
Not all would like this feature, so as a practical solution I suggest that there should be an option in the config that lest you choose wether or not editstep will affect arrow up/down or not.
Waddayasay coders? 
How about the OctaMED way? Up/down steps with EditSteps. Shift (or whatever combination is available) + up/down steps just one line. This way it would be configurable by everyone so noone can argue really 
Johans way is definitely the best. This just adds two more shortcuts, and allows both ways of working at the same time. Less work to implement, more flexibility to use. Not everything has to be selected as options
btw, I think that moving one line per time should be assigned to ARROW keys by default, while moving EditStep-value lines per time should be assigned to SHIFT+ARROW.
this way, nothing will have to be changed
but you forget something : shift + arrow is the instrumentnavigation, else I like the idea
Sounds fine for me 
And then you can reassign them with the keyboard-assign-function if you want
How about RShift+arrow