On the number of topics, much depends on the content such as
heavy use of graphics, very long topics etc. I think most people
find that around the four / five thousand topic level, you might
see a slow down in performance when you are working on it. However,
it looks like you are way off those figures. Also it does not mean
you cannot exceed them or will see performance degredation, just
that you might. Whether or not it is an issue only you can judge.
On the number of layouts perhaps the only issue is confusing
yourself! I don't think there should be any problem there.
I'll have to leave conditional tag comment to others.
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