Well, it is OK for you to give your own opinions. You have the right to do so. If you give your opinion (which is relevant to the topic, of course) on other people's thread, I think you should go like...'In my opinion,..... Am I correct? I'm not a native speaker, so my interpretation may be wrong.' Otherwise, learners(especially beginners) are very likely to believe the information provided by you is all correct. (I know you always include 'a learner from Bosnia' in your post. Of course these words let us know that you are not an expert on the English language. And I know you are trying really hard to learn, judging from the long passage you provide to us.)
We are not playing with words.(Well... sometimes yes)
We are learning a language, right?
Starting your own thread would always be a good idea.