Generally speaking any positive contribution can help. This includes suggesting edits.
However, based on observations and previous discussions on the question ban, it appears to be extremely unlikely that only editing will lift the ban, especially if you have several heavily downvoted posts. The fastest way to lift the ban is to fix your old content. Try editing your questions so that they are more clear and conform to the guidelines of the site you are banned on. Upvotes on those posts will do more to lift the ban than anything else.
I do have to take exception with a couple sentences at the end of your question
If you are banned from answering, you can ask good questions, whether you are a noob or not.
This is not a true statement. As you have found (assuming a question ban led to you asking this question), asking a good question is a difficult skill. Not everyone can ask a good question easily, so to assume that just because you know something means you would be skilled in asking about it is not a fair assumption
However, if you are banned from questioning, and if you are a noob, it's hard to make a good answer.
I think you are doing yourself a serious disservice. Answering questions is not always about knowing the answer when the question is asked. Yes it is true that many new questions can get several fast answers, so if you do not know the answer immediately, it is difficult to answer those questions, but the "Unanswered" tab of your favorite site has vast quantity of questions waiting for an answer. Look for a question in there, find one that interests you, and then try to find the answer.
You may find that the act of researching the answer will teach you more about programming than asking questions ever will, and you may also learn a lot about how do to research, which is critical to asking a good question.