This was her (very rapid) reply:
"I'd probably take the whole thing apart, and crochet around each and every exposed edge, smoothing the jagged steps you mention in the process. Then I'd put it back together, allowing no more than a width of a stitch to stick to the outside."
Doesn't that make beautiful sense? Isn't she wonderful? So that is what I will do, before I give up on the idea of having exposed seams. It's been busy - my parents and Moocow came up to visit - but I did manage to finish one sleevecap.
This just might work! An added benefit is that the slip stitch I did to neaten the edge also has the effect of making the sleevecap ever so slightly smaller, so it should match the armhole much better this time around. Ahh, but I probably won't be able to work on it for a while. I have two midterms early next week, and half of this week is gone already, what with my family visiting. But it was so nice having them here.....now it's quiet (except for my roommate) again.