The only work that my 8 year old does that is close to independent is still done with me in the room, usually at the same table. Even then, it's rarely more than a problem at a time, unless it's her desire to work ahead. Then I let her do as much as she wants.
Grades? What's that? Don't need them at this age.
I don't do schedules. I just pick up the next book and do as much as I feel like. Then pick up the next one. If it's been a while since we've done science, then we do a couple of days-worth of science (or history, or spelling, or whatever).
I'm a pretty relaxed homeschooler.