Trivia rarely affect efficiency. Are all the machinations worth it, when their primary effect is to make the code less readable?
If you had done something twice, you are likely to do it again.
Controlling complexity is the essence of computer programming.
Do what you think is interesting, do something that you think is fun and worthwhile, because otherwise you won't do it well anyway.
Each new user of a new system uncovers a new class of bugs.
Get the weirdnesses into the data where you can manipulate them easily, and the regularity into the code because regular code is a lot easier to work with