I suggest giving province a little bit and getting the claims for champagne. Those claims can go away and the cores can't so long as you keep declaring war with france. I don't feel like you have anything to gain with lorraine being a vassal.
Don't worry too much about the culture of the colonies since once you have enough in a colonial region it will form a unified colony under you. Don't make it too big to start off (as their modifiers are rather large for their armies). They usually form when you have five colonies set up in a colonial region. Don't worry about trade in that area as tariffs will help initially one the colonial nation forms.
Also about the North Sea merchant. Check it and make sure it is going to Antwerp because I don't recall there one being there. Pulling from lubeck might be more lucrative and forward to lubeck in the north seas. This will help you pull in a lot. Lubeck is a huge node to pull from.
I see where you are going but his war cost him a lot. Also, I have notice the amount of war score gained to go up after leaving out small one province nations. also, having them out means less rebel chance from since less occupied territory.