I am still playing Japan and Britain is close of winning (97% of PP and four times the second (19800:4520)). I think the PP concept is misleading like in Victoria2.
It is unhistoric. I think it would be better, when each country had their own goals to meet like winning territory, get market leader, or so. The miniquests are quite that right.
In fact don't forget, the 19 century was a civic one with the economic and political power slowly but unstoppable shifting from the aristocrats to the middle class. In 20. century the laborers were included in this. So all what this people didn't like was war. There were only few wars between grandpowers after 1815 in europe. So i think, each contry should have their own diplomatic goals, for Britain and France, go for a cheap victoria against tribes in Africa or Asia, for Prussia and Italy go for unification, for Russia and Japan go for modernisation and last for Austria hold your line. And USA go for destiny.
But avoid wars against each other.