Topics I have posted in
Subject: I
Verb: have posted
Object: topics
Adverbial phrase: in ... (In? In what?)
The parsing above clearly demonstrates the grammatical inaccuracy of the sentence under review. The sentence is incomplete.
Aw look what you done, now he ain't never gonna to write no more posts here.
Didn't read this whole thing (yeah, that's short for "I did not read this entire set of postings"), so somebody else may have already said this, but in my experience almost nobody understands what the word "only" means. As in, "I only played one game" or "I only had two eggs" -- certainly very common structures. Phrased in this manner, the only excludes everything other than "played" or "had" -- I had the two eggs, but nothing more. Did not eat them, cook them, look at them, purchase them, digest them, ... Clearly, the intention is to exclude numbers beyond two, so it should read "I had only two eggs".
I only had two eggs might also mean I, but nobody else, had two eggs.