Wow, Laura, this sounds exactly like me...except that my muse decided to revist the story. My story was "Chances Are", written 7 years ago when I was 17. I try not to go back and re-read any of my stories. It makes me cringe because I'm so self-critcal. I'm now in the process of re-writing and posting
this story as "Wherever You Will Go".
Anyway, in answer to your questions:
a)Don't take it off the archive even though it may promise more
b) I personally suggest option b if you're up to revising it a little. Who knows? Your muse might take off with it and write that series after all.
c)Leave it as is if you want to. No harm done there. I'm sure there are plenty more out there like yours and people understand.
Sara (who is wondering just what story it is so that she can go read it and properly nag for a finish
)