Integrating a vassal with colonial nations makes those CNs yours; I've managed to get 3 merchants out of Brazilian CNs beforeIf I will Integrate Spain that owns lets say 10 province Caribbean colony and own 10 proince Caribbean colony will I get 2 merchants? Will I get same amout of Trade Power like for one colony?
If I claim Spanish Throne and PU them (30k army of Spain is stuck in Mali) will I get PU over Naples? When you lose historical friends? Can I win war without losing this?
If you claim throne and force PU vis war, you get all the PU juniors also.
Historical friends disappears if you have a battle against them; war itself doesn't necessarily lose it, though winning said war without fighting any battles is an interesting challenge. It can be done if you have big vassals or allies.