I hate grading!

So I noticed while I was grading the Math 5 projects over winter break how much I hate grading. It's so arbitrary. Another intern asked me how grading math could be arbitrary. If I'm giving partial credit based on a student's work, I have to make judgment calls on how much each mistake is worth. Is this mistake worse than that mistake? What defines a conceptual misunderstanding, and what is just a silly mistake?

Furthermore, I've found that we don't do a very good job at creating tests/quizzes/projects with grading in mind. For example, with this project, we just asked them to do 38 problems out of a textbook and told them we'd collect it for a project grade. Since it was a project grade, I couldn't just check it for completion, I needed to grade it for accuracy. And 38 problems per student was a lot. So I wanted to give them a lot of credit for working so hard, but I also didn't want it to change their grades too drastically this close to the end of the semester. But then I didn't want to make any one problem worth more points than another because we hadn't told the students that certain problems were more important than others, so that didn't seem fair. My point is that I think it's important to set it up in advance how many points each problem is worth, so that both the teacher and the student know what's important.

I also want to address the attendance policy. I don't believe that failing a class based on attendance is fair or helpful for the student. If a student is 10 minutes late everyday yet understands the material and does well on all the tests and quizzes, it's not helpful for the student to retake the class in summer school. A grade should reflect how much the student has learned about a subject, not their attendance, their behavior, or their level of responsibility. I strongly believe grades have lost their meanings, and we need to separate these student skills from their understanding of the content. Sure, presumably in most cases, these student skills will help a student to learn better. However, it is not always the case. I'm not saying that we shouldn't be evaluating their attendance, their behavior, etc. But they cannot be factored into the course grade the same way. Maybe they get multiple grades for one class, I don't know, but I'm tired of seeing students fail classes based on their punctuality. It truly makes the grade lose any sort of meaning.

So the question is... how do I hold my students responsible for attendance and behavior without giving it a huge impact on their grade?