Anthony:
You've listed a lot of good factors that bear considering.
Student learning outcomes (SLO's) define what a student should learn, know, perform, assess, etc. at the end of a course. I believe that if we teach to the SLO's, then assessing if they have achieved those goals makes grading a bit easier a task.
How we go about setting up those assessments still needs to be fair to all students and consistently applied in the same fashion. A key is to assure that the students know what the expectations for grading are at the outset. This helps minimize disputes when the grading process is finalized and posted.
Regards, Barry