Anonymous“Are all these statements correct? Are they
the same meaning? Can we put
the adjective in front of the gerund like statements no. 3 ?”
The first two are correct. The third is correct but
awkward. The meaning of the first is only slightly different from
the meaning of the second. In the first, you're not interested in
the topic, no matter who does it, talks about it, writes about it,
etc. In the second, it's your own personal participation in such
activities that you're not interested in. If the context is
right, the first can take on the meaning of the second, though.
Gerunds
can take adjectives in general, but the effect is a bit awkward in this
particular example. So the objection here is one of style, not
grammar. 
CJ