I never claimed the monarch was needed for protection. In the UK, "The Crown" also refers to state, for instance in a court case "John Doe" decides to sue the country which would be refered to as "The Crown"

As for what the House of Windsor has done (Originally under a different name, of course) It has voluntarily surrendered more and more powers when called for by the people, appointed governors for territories (colonial peroid, though this task was of course shared with parliament) appointed governor generals, intervened in diplomatic processes where need be, been a symbol for the British people, visited the soldiers on the lines (World Wars, paticularly King George in WW2) participated in the creation of the UN (George again, his contributions were small. admitedly) Voluntered to storm the beaches on Normandy (George again, stopped by Churchill, both wanted to go. Some say that George actually volunteered to invoke a "If your going I'm going" sort of thing to stop Churchill going.) Served in the military (a variety of members), participated in charity work, headed the Commonwealth of Nations, trimmed a couple of quid off my taxes, made the UK a fair bit of coin. And generally, they've been dutiful.

They've been good to the country, and the country has been good for them. 

As for an inheritance tax, are you proposing to only tax the rich? If only! The rich wont even accept a tax on their houses for lords sake, good luck putting in an inheritance tax; Which doesnt really fix the problen at all and people will just circumvent...

And honestly? Luck plays a massive part in our lives. Some people will be lucky, some wont. That'll never change. There will always be the advantaged, there will always be those who were born undeserving of it but rich, born deserving but poor. The only way to fully change this is to jump in on the extreme ends, which brings its own problems.