Hahahaa...that was a pretty sneaky little idea. Making Fleur promise herself as a slave to Harry until the wedding...only that there will BE no wedding! :D
If I understood correctly, Bill will die at Mistress Shadow's hands (erm...you really could have selected a better name for her :P) so Fleur, basically, is Harry's slave for the rest of her life :D
Great fic, and very hot...I wonder if my pleading you will make you write a long smut scene or 500 of them? :)
Good luck writing, I hope you continue this fic.