Thank you! I should note that Pyoverdine doesn't currently work in the ways you describe -- I kept it pretty close to reality and AFAIK it doesn't *oxidise* iron, only scavenge already-oxidised Fe2+ ions. I do like its "puzzle" nature -- a spell that makes goo that *stops* glowing when it touches metal; what uses will players devise? Your post does give me ideas for making it --or perhaps some other secretion spell -- more flexible.
I still need to clean up their formatting, and actually write a proper description for Kleptoplasty!