4) It's helpful for students to get frequent and quick feedback, especially on papers. When drafts are not graded students put far less effort into them. Your system would need to involve someone grading drafts of papers.

As a graduate student, I cannot agree more. Frequent but only semi-significant marks are the best learning tool: significant enough that everyone has an incentive to do the work, insignificant enough that the student can get some of it wrong and simply receive correction rather than failing.

The dopamine kick I get from programming and theorem-proving derive directly from the immediate feedback of something either working or not working without impacting my social status or life plans, allowing me to learn how it's working and optimize it.