When you are a powerfull giant strong power, you have to spread around you conquest. Your first target should probably be spain, russia and the ottoman. You want to take perm from russia to prevent then from getting in Siberia. This is wasteland for you and you don't want to have that land for yourself. You want to isolate Constantinople as fast as possible to get the direct way to asia. This way you don't suffert the different continent penalty.
Spain and portugal are the most anoying colonisation power. If you take down their main land quickly they would stop the colonisation. If you fully annex then you also get their colony. Don't colonise yourself i a waste of time. Just take exploration at the end of the world for the free CB.
Core :
With the new system that allow you to take province for your vassal directly in the war, you don't have to core anything yourself. You will pay the diplo point and the AE yourself, but you should be able to handle the coalition.
Coalition :
To avoid figthing coalition check out when your peace deal is going to end and attack the day after. You might be able to attack before they join the coalition against you. (breaking peace not a bad ideas if you can handle the stab hit)
Spain and portugal are the most anoying colonisation power. If you take down their main land quickly they would stop the colonisation. If you fully annex then you also get their colony. Don't colonise yourself i a waste of time. Just take exploration at the end of the world for the free CB.
Core :
With the new system that allow you to take province for your vassal directly in the war, you don't have to core anything yourself. You will pay the diplo point and the AE yourself, but you should be able to handle the coalition.
Coalition :
To avoid figthing coalition check out when your peace deal is going to end and attack the day after. You might be able to attack before they join the coalition against you. (breaking peace not a bad ideas if you can handle the stab hit)