A few thoughts on the peer evaluation proposal.
Thank you for sharing your valuable experience. In my opinion such an approach would work well for a course which is well moderated and with a relatively low number of students. The problem with it could be that the students among the same group may be friends or become so during the duration of the course and give very good grades to everyone they are to evaluate. Also, in some courses it may not be possible for the teacher to look at all submissions.