Re: Rendering a list of structures - Advice
That's one way.
Generally it's kinda done with a generic object type and the object has info like location and orientation and a member/pointer to detailed geometry, the geometry can be shared.
Your approach if I understand it is inherently sorted by object type which is actually good for state management, a more generic object approach tends to require sorting, yours will too but probably a bit less so.
I suggest you take a look at Open Scene Ggraph.
I'm moving this thread to the scene graph/higher level topics section.