1- Fleets 'landlocked' inside a province and then unable to move out. I have seen this so many times now in the two games versus the AI I have played I can't help but wonder why it wasn't fixed before release.
2- AI Diplomats move to an ocean region and stay there forever, never to move again. Ditto above for the frequency - in fact after 5-6 years of gameplay you won't have to worry about enemy diplomats anymore

3- Lancer build bug, happened to me as both France and Spain. It gives me the option to build yet when I click on it nothing happens except a 'hesitation' in the build queue. Thought perhaps it was a bug with my level of barracks but even after raising the barracks level I get the same result, no Lancer.
More of a wish - I see the tactical AI is being looked into, I hope the Strategic AI gets a good going over as well. One thing it should almost always do but never does is leave an Army or Corps in its home province instead of sending all its troops towards the enemy capital. Looking forward to the patch.
Ron