Hi @lcescocancian,
Here’s a bit about the grading system I’ve used (as it pertains to standards/mastery-based grading): Grading Policies / Creating Student Grades
My categories were similar to yours. I think it’s fine to keep them lumped together like you’re currently doing unless there’s a compelling reason to break them down more. Keeping them lumped allows you a bit more flexibility. When you start getting a feel for how things are working out, then you’ll likely feel more comfortable breaking down the categories more.
As for percentages, I think that’s more dependent on factors such as school/district policy like Terence mentioned, and your own grading philosophy.
I think I’ve heard of other teachers giving a practice Explore as a midterm or final assessment. I used the Unit 3 project (digital scene) as my first semester final project.