1. Scenegraph design would be far better than image points. So I agree. If we can't have scene graph then IP sub folders would be helpful.
3. Is this for types of objects? or how objects are structured in a scene?
a) If it's for types of objects then it's already handled.
b) If it's scene structure. If the system was just already a scenegraph design this would also be handled. Since we don't have that. Then yeah I can see this be helpful.
c) from your sample image, your shooting your self in the foot in regards to C2 sprite management. You should pack your images in to related and/or layer elements of sprites. Then cycle through the animation and/or the index. Each individual Sprite Object becomes it's own texture. Each texture needs swapping in and out of the GPU texture memory. This can increase your drawcalls by massive amounts by making every image type it's own Sprite Object.
4. I don't understand your question? Flexible data type?
It's always better to use casted data types rather than mutable data types. numbers should always be numbers. However what I would LOVE would be to embed more complicated data objects onto a object. As an example
Current variables for objects
[Number, Text, Bool]
Wanted variables for objects
[Number, Text, Bool, Dictionary, Hash List, Array, Custom]
This would be far better than making a container of an objects and linking a Dictionary/Array into the Container.