You have some really nice borders there. I don't. (Click for bigger)
Those are the kind of borders I have nightmares about.
My war-goals are based strongly around creating nice borders. I almost always support Russia's creation and expansion eastwards just to mop up the inevitable easter-border clusterfuck that occurs when Hungary/Austria/Bohemia/Lithuania colonize the hordes.
I also like to have a strong Balkan/Anatolian power to keep things looking nice, but there usually aren't any good (Christian) candidates and the poor Ottomans get inevitably stomped / relations malus from different religions means allying isn't super-practical.
Although it's not very smart purely from a game perspective, I promote the consolidation of larger countries to mop up small nations and see strong late-game powers emerge. Scandinavia (via Sweden) / Russia (via Muscovy) were my two in this game.
Nice job swallowing western Europe. In my Spain game I was looking for a way to destroy France (my main ally, ironically), but they remained pretty strong throughout the entire game, and I wasn't willing to commit the number of troops that it would have required. I actually find it easier to conquer Great Britain, because they almost always get involved in some pointless overseas war and leave their homeland completely unprotected. I don't think I've ever actually seen the British isles conquered by any other foreign power in my games, so my strategy is probably unusual, but once you conquer it, it's so ridiculously unassailable.
In this game, my first priorities were to force Aragon into a PU before it could grow too strong, and have Portugal annexed before colonization started. I achieved both of these by 1450, as Portugal broke their alliance with England (and somehow ended up at war with them).
France is very difficult to take out by force, as you note. Their army is always massive and they are very good at swarming. Annexation means many long, bloody, WE intensive conflicts. So, instead, you should wait for an opportunity to force a Personal Union on them! That way you only need to win one war with them to get them into your realm (You'll eventually inherit/ integrate, although the latter can be infamy intensive) in the long term, and gain control over their endless blue hordes in the interrum. I use France as a battering ram to achieve my other European objectives while they are the junior PU partner.
I think my record was over 3 as Papal States gone crazy. When you get big enough, you have permanent -.8 or so thanks to cardinals controlled, then with an Embassy, Diplo advisor and Cabinet NI the bonuses just pile on top of each other.