Sounds like a great idea; might want to ping a couple of the other people who've started in on this theme; see:
http://forum.shrapnelgames.com/showthread.php?t=43380
http://forum.shrapnelgames.com/showthread.php?t=38268
http://forum.shrapnelgames.com/showthread.php?t=34687
Just a few other things:
Flying Carpets and the Magic Lamp (w/associated Djinni) are already forgeable items.
RE: heroes
Sulayman - if he has dominion over the jann, perhaps he could domsummon (or have summon action) to generate them as troops?
Sinbad should definitely have sailing. Perhaps he could increase the luck scale?
Scheherazade - rather than (just) a mage, she should be a spy and/or assassin? (her description is as a good wife + storyteller, daughter of the vizier, with excellent insight as to the sultan's woes.)
Aladdin - needs stealth. Perhaps should domsummon his "40 thieves"?