I have a single member LLC set up in Wyoming. Actualy, this LLC is 100% shareholded by a Sechellois company of that I'm the only owner. I'm not US resident alien and the Wyoming LLC does not generate US-source income.
yes, if you have an LLC you probably already have to file quarterly or as per your state's regulations. Regardless of the frequency even if you are making zero sales, zero expenses, etc. you need to report them as the files are due.