A couple of points if I may:
1. There is no reason to remove HRH for this pair. Remember George VI insisted that Edward VIII, who was also a senior royal who walked away, kept his as he was always 'the son of a King'. He even went further and gave him his dukedom AFTER he stepped down.
2. Some years ago - in the late 90s I read, and again a number of times in the 2000s that the Queen wouldn't give consent to a royal marriage unless the couple had been together for at least five years. If true she has been proven right as all the marriages and couples, at the forefront of the BRF, since that time that have had those long relationships prior to marriage have lasted - Edward, Peter, Zara, William and Eugenie (well over a year). The only one that hasn't seemed to 'get the message' was the rushed marriage of Harry and Meghan. One has to ask - would Meghan have been able to accept the royal set-up better if she had been forced to wait another year or two? Diana and Charles had about 13 dates before the engagement and both knew it was wrong before the marriage. Sarah and Andrew about the same, with the added complication that he was hardly ever home due to being a serving officer in the navy. Harry and Meghan didn't have enough time together for her to really learn about the BRF and how it operated and now they want to run away, it seems. I do wonder if another year or two dating would have led to this or whether she would have upped sticks before the engagement? Was Harry scarred he wouldn't find someone 'to take him on' so he accepted the first person who did and did so without ensuring they fully understood what they were taking on? Is this what William was concerned about with the reported 'warning' to Harry?
3. I do think The Queen will stop them making money from using their title but insisting that any money made has to go to charity. If they do a talk show or something like that there will be rules put in place about what can and what can't be talked about I am sure. I do think that there will be a lot of 'rule setting' behind the scenes or a complete 'cut-off' even down to finding a way to remove Harry from the line of succession, even if they can't remove their titles e.g. insist that a person must reside in the UK for at least 10 months a year to be in the line of succession (and that would have the other advantage of shortening the line of succession from its current over 5000 down to a manageable 60 or so).