I'm just wondering if there is any functional difference between spins and shans, besides how many fields they contain.

Can I use a spin or shan equally for any graphic? Can I use a shan for a space station with weapons rather than a spin?

Shän and shďp resources are inextricably linked. Spďns are specifically for "everything except ships."

You may use (and reference) the same RLE resources for each -- I have a situation in SFA where a përs eventually becomes a spöb, for instance -- but spöbs always refer to spďns and shďps always refer to shäns.

That's unfortunate. No weapon positioning for space stations, then.

You can create what I refer to as sub-spöbs, which use graphics that are smaller than the primary spöb. You then give the sub-spöbs X and Y coordinates on top of the primary spöb with weapons of your choosing. Thus you can achieve spöb weapons placement to suit your intentions.

I'll keep that in mind, but I'd rather not get that complicated just now.