Should I go for a PhD topic on which I have poor coursework grades?
First, recall that there is nothing about doctoral (or other) level research that suggests all of the necessary ideas are covered by coursework. For those like yourself and others, people need to be able to learn what is necessary to reach the research &quot;edge&quot; and cross it.
You may have a harder time than some, or not, depending on the sorts of things you wind up doing. But don't hesitate because the job looks hard. It would anyway. My guess is that you will be fine. If your advisor believes in you, relax.