The decline of the British Empire is definitely an interesting subject, especially as its territorial peak came relatively close to its precipitous decline. While I don't think the notion of being a former superpower really defines contemporary British politics in the way many outside commentators assume it does, the speed which that decline happened definitely had a marked effect on how our political history played out in the 20th century.

I quite like your proposal for elections too, although its implementation might be difficult when it comes to paper-based electoral systems! It would be interesting to see what effect it would have on the Overton Window, I suspect it would lead to policies becoming more incrementalist and less radical across the board. I would be concerned about it giving more de facto power to the press though.