One conclusion from this seems to be that none of the historical diplomatic, military relations and so on exist from the start of the game. The alliance Russia/Denmark/Sachsen-Poland is not an alliance and not ready to go to war with Sweden and Sweden does not posess any advantages in military development compared to its neighbours (Jack talks about having to research military tech right from the start to take on only one foe).
Incorrect, there are alliances and some factions are at war form campaign start as well as diplomatic relations set up.

Same seems to go for the other major conflict - War of Spanish succession. I.e. it is probably not there at all as a historical event. Successionwars can happen but the startingpositions are all neutral it seems - no alliences and or wars from start and thus litte connection to history and the real challenges these countries faced at the time the game starts.
See above.

As for research, factions start out with a few techs in areas they historically were good in. So Britain with some naval tech etc.