I don't see how it's going fix any of the perceived problems unless I have misunderstood what the 'public vote' actually is. It looks to me like it's just another voting panel added on at the end.
Runaway Winner: Will still happen when one act is so far ahead that no one else can catch up. The 12 points from the public jury won't change anything if the winner is already 13 points ahead.
Nul points: Will still happen if no jury or public votes go to a country.
Regional voting: Will still happen. The UK jury will vote for Ireland, Ireland's jury will vote for the UK, and it's not really that much of a problem seeing as how blocs are rather small and Eurovision delivers diverse results every year.
The biggest spoiling of the climax is that Eurovision themselves choose to announce a winner before all votes are in. It may be obvious that there is an inevitable winner but it puts a complete dampener on everything which follows once that is declared. It destroys the enjoyment of those happy to pretend the field is still wide open until the last vote is cast. It is after all only entertainment.