I guess there will always be exceptions to the guidelines, so I think they are just meant as a helping hand, and if things aren't applicable, then use common sense. I'll definitely adjust the unit test bit to be more generalised for all kinds of tests (like the ones you mentioned).

Do you have an idea on how we can use objective metrics to determine the significance of a contribution? It's pretty important, especially now that they've removed the amount of work as part of the score, since it will probably have the biggest influence on a contributor's final score.