Another Disenchant or Divine Offering would be a good last card.  I think Engineered Explosives may be better than Powder Keg here, but it depends on what you're removing.  I don't like Disk since it comes into play tapped.

Card drawing... Pursuit of Knowledge and Necrologia come to mind, but they are really clunky.  Skeletal Scrying doesn't seem like it can work in the deck.

I'm glad to see people still read my foolishness...  A friend referred me to this and I decided to finally get a tmd account.

I still have a Shahrazad deck, though I generally lend it out rather than play it.  I've made it mono-White due to losing too many games to Crucible / Wasteland / Trinisphere (and this will be an issue even after Trinisphere is restricted, the Crucible / Wasteland is a problem).  I also added the Illusionary Mask / Phyrexian Dreadnaught combo.  Since there are 1cc creatures in the deck anyway, the opponent must plan without knowing what will attack.  The Masks also give resilience to Chalice / Trinisphere.  Exalted Angel is something I've considered, I think it might be best with all the Moxen.  I haven't yet tried putting all the Moxen in the deck.  Your workable black splash intrigues me, Hymn's BB cost kept me away from a black build.

This list is from memory, it might not be quite right.

4 Illusionary Mask
3 Tormod's Crypt
4 Shahrazad
1 balance
4 Phyrexian Dreadnaught
4 Savannah Lions
3 Isamaru, Hound of Konda
3 Soltari Priest
3 Disenchant
3 Swords to plowshares
1 enlightened tutor
2 cursed Scroll
18 plains
1 mox pearl
1 black lotus
4 wasteland
1 strip mine