This is obviously impressive. Did you think from the beginning monolithic/module-based like linux was the way to go or did you consider making it a hybrid/micro kernel.
However, a part of me is feeling like it could make sense to do a big refactor to turn all of this into a micro kernel. However I am not willing to do this until I have a plan to make it right.
By the way, the 32 bits thing too was imposed by the school. I am now wondering if it still relevant to support it and just support 64 bits only...