I'm wanting a competitive deck using Maze's End, and I think that I have one I can use.

http://deckbox.org/sets/373562

Any opinions on improving it?

I could see where you're really going to want some more items to just stall out the game. I'm thinking along the lines of Curse of Exhaustion, Supreme Verdict, Aetherize, Planar Cleansing, Riot Control, Downsize (nobody ever expects the overloaded version, but it buys you turns), Blustersquall (same story), Sleep, Cyclonic Rift, hell, even Sphere of Safety might work.

As a side note, if you want to ensure this thing works, Possibility Storm pairs with Curse of Exhaustion hilariously, as the opponent cannot cast another spell for the duration of the game. Then you could take your sweet time assembling all the gates.

Made a few changes and added a possible sideboard

I would have thought something a little more along the lines of a TurboFog

4 Fog
4 Gatecreeper Vine
4 Greenside Watcher
4 Fog Bank
4 Divination
4 Unexpected Results
4 Tree of Redemption
4 Urban Evolution
2 Staff of Nin

2 Azorius Guildgate
2 Boros Guildgate
2 Dimir Guildgate
2 Golgari Guildgate
2 Gruul Guildgate
2 Izzet Guildgate
4 Maze's End
2 Orzhov Guildgate
2 Rakdos Guildgate
2 Selesnya Guildgate
4 Simic Guildgate

play lands, draw cards, drop walls, play lands, fog, play lands, play lands, play lands, win.
Though you do still need to have 10+ lands in play to win the game. At that point, it is easier to win with just about any other win condition in the game.

At the moment it is more of a situation where I want to use Maze's End as the main card of the deck.

And even with your setup, Hold the Gates would be a really effective thing because with Maze's End decks, you're going to have a lot of gates and giving everything Vigilance is normally a good thing, and with a toughness boost equal to the number of gates you have on the field...

Part of me is also trying to make it a deck that will largely stay competitive post set rotation, and work for the couple block format going this summer for the RTR block

I feel like primeval titan makes Maze;s end insane.... thoughts???

If you were to toss in Amulet of Vigor...