I think you're right that there are certain characters where drawing it the "correct" way leads to a better result, and that there's a reason for the rules (i.e. that the rules are rationally derived). Using the correct order is also probably faster. I think the spelling metaphor is a good one.

I doubt your last claim in the general case, and I think the GP comment in particular is taking things too far -- there's no way that the average Japanese reader is going to be able to tell the stroke order used to write ぉ (in handwriting scenarios, not calligraphy), so long as you don't mess up the form of the thing.