"눈팅" - "watching" or "lurking". It means just following what goes on (on an internet site) without participating in the discussion or a game. "I think..." can be expressed as "생각하다"(opinion, judgement) or "~ㄴ 것 같다"(broader). Examples: - 그것은 옳지 않다고 생각해요: I don't think it is right. - 비가 오는 것 같아요: I think it is raining. You can also do a search on "고 생각해요" and "것 같아요" (with quotes) to see more examples.