But no, I am not confused about the symbolic roles vs what is written in law.

I am an indian and our current Parliamentary system is a British legacy. We understood the need of a titular role like the Queen in our system, and thus created the position of the President for it. So in India, everything happens in the name of the President of India. E.g. A law becomes a law only if the President signs it. However, our constitution clearly defines the role and the post has no real power over the Executive, Parliament or the Judiciary.

Personally, my perception of the British monarchy has been that the laws assigning the power to the monarchy, as it was then written gives them a lot of power. But it is only in the last 3 - 4 decades that they are being interpreted more "democratically" in modern parliamentary traditions (a reflection of the changing times). And thus it is being taken to mean that all her powers can only be exercised "under the advise of the cabinet", even if some of the laws don't explicitly state that. (As you rightly pointed out, the lack of a written constitution is a very interesting feature of the British system, as it allows for a more "flexible" interpretation of the law by the courts).

Interestingly, unlike in the indian system, a Queen can actually refuse to sign a bill into law. (In India, it is clearly spelled out that the President can refuse to sign a bill into law and send it back to the parliament with his objections. But if it is sent back again, the President has no choice but to sign and make it a law). So in theory, the Queen can over rule any law abolishing the monarchy or its role in the British system! There's also enough leeway, in theory, in the laws for the Queen to assume full power anytime in the future as the Queen can dismiss an elected government and elections can only be held when the Queen calls for it.

> The power to go to war used to be a Royal Perogative (the PM could declare war) but even this is now lost after adventures in Iraq and requires assent by parliament.

If I remember right, didn't the Queen refuse to give her assent to table this bill to the Parliament? (One of the rare times she exercised this power).

    In one instance the Queen completely vetoed the Military Actions Against Iraq Bill in 1999, a private member's bill that sought to transfer the power to authorise military strikes against Iraq from the monarch to parliament.