This is something definitely doable in XNA. Let me get some specifics first. Fish are draggable between RU's and RU sections if divided, correct? I assume they "snap" into a default position when the mouse is let go? Do the fish drag as a group or are they dragged individually?

Dividers, can they be freely dragged up and down or are there specific positions? How do you handle adding and removing dividers; do you drag them "off" the RU to remove them? When adding them, do you rt-click a context menu to "add divider" to the RU?

How are the RU's arranged in your application? When you open this form, are there like 50 RUs on the form where you have to zoom in on the ones you want or only 2 or so like you have drawn? I'm not clear on where you're zooming and why.

Icon positioning, rotation, scaling, tinting, zooming are a non-issue. That's just a little math.

Finally, what's your design constraint as to why they have to be Pictureboxes?