Started a few games, the one I've stuck with is Milan, aim is to take over all the provinces in the Genoa trade node and start building tall, as an Ambrosian Republic.
It was going great, allied Austria early and swept up a few neighbouring provinces, picked up alliances with France and Aragon as well. Burgundian inheritance fired and France kicked England off the mainland completely. At some point apparently, I declined a call to arms from Austria, but I'm pretty sure I never got a popup about it, which annoyed me.
Just taken a couple of provinces from Savoy, and it's finally triggered a coalition against me. Which wasn't a huge concern given my allies, except when the war actually fired, France dishonored our alliance and left me in lurch. Luckily I've allied Poland, who have their PU over Lithuania. But I'm now at war with a bunch of HRE minors and Bohemia.
My alliance has more troops, but we're separated, so the war is going to be long and expensive. I expect I'll need to take a few loans out to survive.
Still, enjoying it. Not sure how I'm going to take the land from France in the future, might need to go south through Italy first.