Update:
Ended up giving up on attacking Portugal. Couple odd things contributed. First England is just beating the tar out of France so I can't attack Portugal or England with help from Castile without just getting spanked by England (I did some save scum tests). Second, Castile did attack Granada but only could take the province of Granada because it was starting to lose to the Granada/Tunis/Morocco alliance. Third, I did a No CB on Granada, took Gibraltar, gave the other Granada province to Castile but I then took the southern most Morocco province. With that province I no longer needed to attack Portugal in order to Colonize.
So far I have 2 colonies built in the Caribbean and 2 in progress. Castile has unlocked 1/8 exploration ideas, but nothing further so isn't a colonial competitor yet. Portugal, luckily for me, has only unlocked 3/8 so only has 1 colonist...which is fantastic because he settles colonies so much faster even though I'm maxing out all my settler bonuses (it's currently 85 to 65 or something, but at one point it was 110 to 65 settlement rate).
Once Castile unlocks his 2nd idea I'll have to start colonizing Africa so I can grab all the important Centers of Trade (CoT) since that's likely the only place he can colonize at first. Portugal, while screwing me over, colonized both Arguin AND Cape Verde, which is going to prevent Spain from Colonizing for a bit which is an upside to me not being able to colonize those two locations.
England has also unlocked Exploration, but hasn't start colonizing anywhere. He probably needs more colonial range. Norway has not unlocked Exploration and neither has France. Least not yet.
I'm allied to Castile, Hungary, and Portugal. It's doubtful I'll stay allied to Hungary or Portugal forever, but with Portugal there's always a chance I do. It really depends on what England does vs Castile. Castile is attacking Aragon right now with my small naval assistance. He might be able to annex him. If that happens, I'm not sure if Castile then absorbs the PU over Naples or if Naples is automatically independent. Oh and btw Burgundy succession crisis never happened as you can see above-probably a small reason why France isn't doing so hot; though in France's long term favor, Burgundy does not like England.