Only 19 out of the 28 european union members use the euro. So I don't think the euro (a 19 year old currency ) is the answer. Unless something changes, then in the future it might be one of the answers.
> you won't even have to worry about the brits messing with it...
The brits never adopted the euro as their currency, so they never messed with it to begin with.
> Stable, inflation proof, light or no sanctions. As brexit proceeds a
Stable... brexit. The problem with the euro is that its political foundation ( european union ) seems weak. With britain leaving the european union, with the EU sovereign debt crisis and potential for further problems in the near term, it's more likely the EU will break apart and the euro discarded than the euro will replace the dollar as the reserve currency of the world. Being the reserve currency of the world requires the political and military backing of a stable superpower. For all our problems, the US isn't losing states like the EU is losing countries.
If the dollar's stranglehold in the world break, we'll probably get regionally dominant currencies. The dollar will still dominate the western hemisphere. The eastern hemisphere will be dominated by regional economic powers and their currencies.