Totally agreed with your thoughts. I had followed the same learning pattern like you
Instead of using the list box you can use the slider with variable to filter the data. Visually they look very appealing and also user friendly. I would also recommend you to learn Indirect Set Analysis... which is very useful. I am attaching a pdf document.
If you need further explanation, then please post the QV document with sample data and I'll quickly mock up an example for your reference.
Cheers - DV
You're probably getting 404 errors because QlikView recently completely changed their site. All old links are now bad links. The content has been copied across, but not with exactly the same addresses, and often not with proper formatting I've found.
I agree that the QlikView help file is a bit unhelpful unless you know exactly what you're looking for. "How do I do this?" isn't answered in there. It only contains information like, "What is the right syntax and examples for this specific function." It's more like a short reference manual than a "how to".
I'm afraid I'm not understanding what you're after, though. If you just want to choose and compare different weeks, have a "Week" field in your calendar table (we typically build a separate calendar table in the script when dealing with date date). The users can then select two weeks. If a chart has week as a dimension, they can then compare those two weeks side by side. No need for set analysis or variables for something that simple. Of course your situation may not be that simple.
Hopefully when you post the example you mentioned it'll all become clear, and we can get it solved for you.