I tried a game out as Portugal and was abit disappointed that there wasn't much flavour out there. So, just wanted to make some suggestions:

1) When playing as the Byzantines, maybe have a decision/event to actually launch the fleet? I didn't even realise my great fleet sailed out. This way we can also have more control on the preparations, so maybe it's a case of having time to gather resources vs. Ottomans attacking.

2) After the fleet sets sail, maybe give an event for Castile or Portugal where the fleet asks to stop in Canaris/Azores for supplies and people? The player can push ahead without stopping but runs the risk of losing more stuff over the ocean, whereas if they stop there's a small chance the host nation will find out where they're going.

3) 'Byzantine Demise' modifier: rather than just disappearing, I think this should be removed to whoever discovers the Norse or Elysium first? So an England or France can discover it too if they find Bermuda or Vinland.

4) In addition to 3), the discoverer can choose to either sell them guns or try to conquer them. If you're portugal, then you'll be asking for the boats back with interest for lying...

Just some thoughts!