I took EET's review courses last year, and they didn't have any requirements on completing/submitting the homework problems. They had started administering "mini exams", which were 10 question tests on a given topic, typically sent out after they had finished the lectures for that topic. Then they would give you ~1 week to get it done and resubmitted to them. You were only supposed to spend an hour max on them (10 Q's @ 6 min), but they would sometimes take me 1.5-2hrs to finish them.
Unless they've changed their participation requirements, the homework questions were just to be done on your own time and not turned in. I'm not sure exactly how many hours a week I spent on the homeworks. My typical studying time was ~15 hrs/week, split up into watching lectures, doing HW problems, etc. The amount of problems they provide to you were pretty proportional to the exam distribution...only like 4 questions about cold form, and up to ~40 questions or so for steel & concrete.
Hope that helps you some.