I added Alarm to help vs other lock decks (stax, tnt, ect)
I'm a pretty serious WelderMUD player, and I'm pretty sure than people other than myself are playing Chalice of the Void in addition to the lock components you mentioned. I would forsee a difficult 1st game against a prison deck that's packing them...set to one, it stalls your whole engine.
Is Timetwister included just for Power kicks? It seems like if you get artifacts out of your deck and into your graveyard for Welder, that would be a good thing.
Lastly, your red mana base is in a lot of danger from a full compliment of Wastelands, not to mention a resolved Blood Moon guarantees that you can't cast any blue spells off anything but your Mox Sapphire/Black Lotus...2 out of 60 ain't good odds.
I realize that's a lot of criticism without much suggestions for improvements. I'd focus first on mana base, taking into account Blood Moon and Wastelands (which you'll see from many TNT/WelderMUD builds), and heavily recommend Rack and Ruin sideboard, as well as possibly including Gorilla Shaman...as I forsee you playing first in the second game of the match against a heavy prison deck, and you may be able to drop it first turn, gaining you significant advantage towards blowing up Chalice/Sphere. If they're playing Trinisphere, don't even bother with the Monkey.