Helmuth, WELL put! I think you would make a great moderator for the actual Brainstorm site.
The only quibble I really have is with the term "wontfix". That tends to be a psychological hot button. I'd rather see less hostile resolutions like "CAN'T do" or "no need (and here's why: ___)", etc.

As for levels... I want to make sure I'm clear on what you're asking. Do you mean proposal/solution, or 2 levels for solutions? Maybe "levels" was the wrong word for me to use for solutions... "scope" might be better.