I like the litter thread because it's a simple topic that everyone has an answer to and also because the thread writes itself. From a simple question you'll get answers that spark a discussion about the ecological impact of littering. You need to decide what type of thread host you want to be. Do you want to be lassiez-faire and let the thread run itself or do you want to guide the thread along into deeper discussions about your base topic.
You can be a hero or a villain, the choice is yours.
I see you started off on the wrong foot here, you made a bad bet and got burnt, it happens. I think one problem is you asked too many questions in one thread. Almost each of those could have been it's own thread, so don't think about it too hard, just ask a question and see how it goes, I think you have some good thread ideas. Once you have asked enough questions you start to get answers and then you have enough material to make your own opinion pieces.
Having some failed threads is good, you'll know what works and what doesn't. This time people thought you were trolling and the mods got involved, other than getting banned that's the worst case scenario. I would try to avoid making comedy threads for now since people have to know you're joking else people will just get confused and get angry.