One other thing that I think is worth pointing out is that questions that are closed needn't stay closed. So editing your original question to explain why the answers on the duplicate don't help you is a good thing to do as it can lead to your question being reopened. If you think that you've edited it enough to be distinct from the duplicate, you can flag it for moderator attention and one of the moderators can reopen it.
(The community also has the power to reopen it, it takes 5 votes to do so or one from a moderator. Given that people are probably less aware that a question is awaiting being reopened than they are of one that is in the process of being closed, I think that flagging for moderator attention is absolutely fine in this case.)
I notice that you now have 56 reputation so you should be okay to comment on the duplicate if all you are looking for is clarification.
Also, your suggestion of people with low rep being able to comment on the duplicate is a good one. But here isn't the place to make that suggestion. So I've posted it on meta.SO.