Categories trimming?

One issue I would like us to discuss before we open these forums to the world is categories.
I came up with a fairly detailed list, on the basis that I don't want forums to include topics that have nothing to do with each others.
What I mean is that there is kind of two options: either we have only 2-5 categories, or we have 30, as we do right now. I don't believe there is an intermediate solution. But of course I can be wrong.
Please comment at will on what does not feel right in the current categorizing, and propose alternative. We can discuss them in this forum.

Perhaps there are too many sub-subject in the "software" directory.
Some of those may be confusing with the "Theory and Concepts" directory, e.g. "control & reconstructor"
Sometimes, it is difficult to clearly separate "software" from "concepts".

I don't disagree with you. "reconstructors & control" in software was more for implementation issues ( opposite to "theory and concept" where it is more...well... theory and concept).
Others, any vote on this issue?