Nat - Thanks for visiting the site and I hope you find/found something there that helps.
as far as teaching TOEIC and test English to elememntary students...
This applies to teachers outside of the school system. I assume you are in that case since the mothers are trying to influence what's being taught.
I'm in Japan and I have to admit I'm ignorant about the system in Korea but I'm pretty sure it's similar. These kids are going to get all the test English they need for 6 years in junior high and high school. If you do it with them they are just going to repeat in JHS and HS and waste their time with you or at school (however you want to look at it.)
There may be certain reasons to teach English for exams with ele. children; if they need it to get into a private or high level JHS or HS, for example. (not that it's the best for them but if that's what you're paid to do...)
When teaching for tests, the teacher ends up structuring lessons according to what is contained in the test suited for anyone around the world, not nec. what your students need right now. I believe that teaching for exams will lead you to students who can just do well on tests. That's a generalization and there are plenty of students who can make the leap from the textbook to speaking, but the majority can't.
Tests are a quick measure of progress, but not always true in my opinion. I tell mothers and other teachers, it's a long race and we're not looking to finish tomorrow. So, our goal line is way off in the distance. We need to go slow, take care and pick up provisions along the way for the long haul. If we sprint to the next rest stop, we'll loose half the group and some might die!
Anybody can study for a test on their own. If it's what the student or parents want them to do, get them a test workbook with explanation and assign it as hw. Then answer questions or address problem after class.
I know that doesn't answer your original question (and yes, I also believe it's how you use a course book.) Being in the test system here in Japan, this is just what I was thinking rereading this.