Why use three command blocks, when one would suffice?
For a developer, the standard
|| operators would be pure gold. This would also require commands to have return values or exit codes, which is simple enough to implement as well.
This would allow multiple commands to be run from the same command block, which for example would allow you to use a testfor and the target command in a more compact way.
In the same category is the “end of line” character (represented by
; in every object oriented language that I can think of) which would allow the additional commands to be executed regardless of whether or not the previous command was successful.
This time, rather than create a mod for the features I want, I added the suggestions to Reddit (so if you use Reddit, show them some love):