I think this is wonderful and LONG overdue. Good for the Queen for not caring in the sense of if they have a girl then a boy, the boy gets to be ahead in the line. It is 2011, this should have been changed a long time ago.
Now, I will give you Brits credit for this. In this country, we have a saying about family fortunes, houses, wealth, etc. The grandfather builds, the son lives off of it, the grandson destroys it. Hence why the Vanderbilts, as an example, no longer have the immense wealth.
BUT, with your aristocracy....what impresses me, is that many, many of them have been able to maintain their properties, wealth, etc., for hundreds if not thousands of years. I like to read about them online...and as an American to see this, wow. Granted some of the homes have been sold, contents, jewels, etc...but a ton of these families have been able to keep it intact due to primogeniture. I am not trying, as a woman, to sounds sexist...but that is impressive.
As for the ban on Catholics...simply do this, make it clear the sovereign MUST be Anglican...no matter the religion of the parent who is not. This is not difficult to do IMO..and I am a Catholic...lol.