The situation after some more wars...
I am not sure if it is impossible to win now, Sicily has three colonies and i could not find the last one- it is not in my line of sight- so i could not annex them. The plan now is to make them release Naples in Sicily and then annex Naples.
In the big, though uneventful war with Castille i only managed to take five provinces, kept one and used the other to release a crippled Algiers as my vassal. I also forced them to release OPM Fez...
It seems i will have to end my alliance with Muscovy, so as to ally with Burgundy which is the only western power with a serious navy. Then i can dissect Castille for good.

I am not sure if it is impossible to win now, Sicily has three colonies and i could not find the last one- it is not in my line of sight- so i could not annex them. The plan now is to make them release Naples in Sicily and then annex Naples.
In the big, though uneventful war with Castille i only managed to take five provinces, kept one and used the other to release a crippled Algiers as my vassal. I also forced them to release OPM Fez...
It seems i will have to end my alliance with Muscovy, so as to ally with Burgundy which is the only western power with a serious navy. Then i can dissect Castille for good.