I love the entrepreneur! I am also glad you have opened up. I know a number of serial entrepreneur households with diverse businesses and they all keep them separate - including me...My wife runs
Js Design and even the on and offline retail business version of this business (launching soon) will be separate for many reasons. The holding company you are looking at may not be required for what you are doing.
What will keep you life simple (good luck with that), you will need a great CPA/business advisor - that is what you need!