To me, the national focus tree structure makes no sense. It's probably because I haven't played the game yet, but I just don't see it working and I hoped that with the WWWs and DDs, I'd understand the vision.
If it's something like tech, research trees are quite intuitive. You research the Vickers II, because that gives you the experience, the know-how to build the Matilda and newer ones that rely on that initial design. It might be even more detailed, as in HoI3 with dependencies on the engineering skill of engines, ballistics and so forth making an impact on progression or you can rely on production lines to give you that extra complexity and reason to consider what advances you want implemented, it's just as meaningful.
However, when it comes to the decision to "liberate" Norway, why should it depend on the previous Scandinavian intervention? More importantly why should it depend on a fixed event and not something dynamic that happens in the game. I.e. what if Finland and Sweden secure non-aggression with both the USSR and the 3rd Reich and Norway gets invaded only in 1944? There shouldn't be a "need" to intervene in Scandinavia, but a national consensus on Norway alone, that needs to be built before the political leaders can muster enough support for the decision. But it needs to be a dynamic decision that considers in game events.
Also, Embargo Germany... why? What if they choose the democratic route, a decision that might let them gain territory only when the soviets, Japan make enough fuss that the world descends into chaos? Britain should want to embargo any rabble-rouser causing such issues, not necessarily Germany. It should be a dynamic event, not fixed in a tree decision. Also the players should be able to define these goals with what actions can be taken and the success criteria of the decision (i.e. less than 20% of shipping gets through the embargo of the country causing havoc on the old continent).
Later edit: also, solving engineering challenges shouldn't be a decision you have to make against political choices, they should be completely separate decisions, on separate pipelines as they can be performed by different factions within the government. The technological advancements of armament should depend on engineering prowess, political choices on type of government, circumstances and people in charge of various political aspects...
