TFSAHad to do some searching as I have made quite a bit in my TFSA. As is normal, CRA will not tell you what you are allowed to do in a TFSA. They will only tell you after you have broken their grey rules that nobody knows about. This is the answer I got from someone I trust...
Your question falls in a dark grey pit, as you know. The best answer i could find is from Advisors Edge and says "The CRA has said that it looks to set of factors to determine whether a TFSA has been carrying on a business, including the frequency of trading, whether the TFSA holder has specialized knowledge of the markets, and the time the TFSA holder spends on researching trades. The government did not provide any additional guidance to taxpayers of what it considers to be carrying on a business"