Depriving the Royal Family of its control of the Royal Collection is one thing but you do not submit any proposals for what you suggest is done with it. Sure there can be 100 select committees griping about it but there is no British Louvre to house it, the UK taxpayer does not currently fund it and I suspect would be reluctant to hand over the $200 million the French taxpayer pays for the Louvre (albeit 95% of its collection is not visible to them).
So what happens to it?
As I say the Royal Collection faces a serious financial crisis and it may be at some point the Royal Family feels compelled to invite the Government to take control – a good example would be the Hanoverian castle example. I am personally ambivalent about ownership because if the collection was suddenly transformed, I do not consider anything would change.
I think your penultimate paragraph is the most important. It seems evident that you want a wholesale investigation to the wealth/assets/powers of the Monarchy. Again, that is entirely your prerogative. Whatever the long-term merits of such an exploration, you will appreciate that will be resisted by the Royal Family at all costs.
Can you please confirm which Bill the Queen has refused to sign? The last British monarch to sign a Bill was Queen Anne.