the idea is sound, but the deck you've created isn't exactly fool-proof...
Personally, I'd forget the Gifts Ungiven and use intuition instead, also cutting both chains and btb down to three... that also makes space for three cunning wish (only 3 intuition, 4 is overkill).
As for the manabase, I think Toad's forgetting what one of my friends said a little while back:
"In the current meta, BASIC LANDS are TECH!"
and he's right, the blood moons, the wasteland-crucible-exploration decks, blood moon, etc are forcing people to rethink all their expensive duals...
The deck needs a "draw" engine. Without ak (which says "draw," btw) intuition is just a crude tutor.
Yes, basic lands are tech, but 13 blue sources was certainly not enough to support drain and I want to maintain 7 black sources for the splash, ALL WITHOUT cutting any artifact acceleration or strips, and without increasing the count of the mana base beyond 27. Thus, 2 underground seas are the solution upping the blue source count to 15 for drain while still supporting the slash. Only 2 non-strip non basics isn't a big deal.
After testing a chains build I will have to say that the problemwith chains is this any intelligent player will be able to work around it and not be as affected by it. Generally what it really does is make them gas up a huge yawg will. I know this deck is supposed to win at the draw/go time but i dont think it has the staying power. 10X counters is great but with no real draw engine to speak of there is no power behind it. smemenenU wins because it can dig out the answers and it packs the extra 4 counters.
I know the above is moderatly intelligent so im going to kill it with some really bad tech for the finisher. thought of using finkel yet? Draws cards sure but also has the phear ability.
Gifts ungiven, albeit crappy, is a draw engine and it is the only real draw engine unaffected by chains.
I don't see how they should be able to keep up even with your crappy draw engine if you resolve a chains or b2b. If you do, either: any brainstorms, thirst for knowledges, or even scryings, etc, your opponent has suck, while your gifts and impulses work fine, OR, their mana base is completely crippled while yours works fine. I don't see how they can work around it when the only real draw spell that is now usable for them to gain card advantage is fact of fiction and most decks don't pack more than a few basics compared to your 8 and 4 fetches to grab them out. Barring extraordianry circustances, how can they work up to resolve a big will in this situation, and if they can, why is will so scary if it doesn't allow them to abuse spent draw spells?
I actually heard about a U/B control deck using finkel and being a variation on mono-U (it won a 95 person Vintage tourney), but as this deck is based around chains finkel has terrible synergy with it.