Hi there!
This is a simple zoom plugin designed to only use the default zoom system RPG Maker has and don't let the user acces it by default. As so, yes, the zoom on an specific character, will not make the camera follow it.
The same for the pictures. The pictures are place in screen coordinates. When you zoom, they will not update their position according to zoom.
My suggestion is for you to take a look at Galv zoom plugin. I think he has one.
I may update this plugin one day to include this features. But not for now.