doctorhydrogen

I'd find a slot for Vault of the Archangel. It's a house. I'm less of a fan of Dryad Arbor, though. I run it in Edric because it is one more creature I an swing with early, but outside that it is just a land drop that dies to the first board wipe.

Quicksilver Fountain is pretty solid in mono-blue.

Even with the few non-basics you're running I'd consider Back to Basics as well. It can cripple multi-color decks.

Black Market is amazing, but it (and Necropotence) paint a huge bullseye on your back. Myself, I like cards that are sneaky good but don't make people gun for you, but that kind of thing is largely meta-dependent.

You have two copies of Lightning Greaves, Path to Exile and Blazing Archon.

I'm a fan of Aurification and Fight or Flight. FoF in particular has some political ramifications, as you can choose to put zero creatures into a pile for an opponent to reward him/her for not attacking you, etc.

Executioner's Capsule w Glissa lets you chain-kill stuff.

Yeah, 48 is way overkill in a mono-deck. 38 tops, and even that seems high.

Nykthos Shrine to Nyx would shine with all those white mana symbols.

Crackdown and Mass Calcify fit great in mono-white decks.

Condemn, Oblation and Swords to Plowshares are all cheap and amazing.

I'd run either Revoke Existence or Return to Dust over Cursebreak.

Deadbridge Chant puts a lotta stuff in the yard and gets you a draw for stuff you can't dredge.

Oh, and just a general thing I tell all my friends who have fetches in EDH decks but are on a limited budget; if you can find ANY possible way to make a trade to turn your fetch into a ABUR dual, do it. Fetches WILL get reprinted at some point in the next couple of years, and at that point your fifty (or more) dollar card will be worth ten bucks. ABUR duals on the other hand will never be cheaper than they are now. Myself personally if I could find a way to swap or sell a Marsh Flats to pick up a Scrubland or cash to buy a Scrubland I'd do it in a hearbeat.

I saw the Vindicate (and Ashen Rider), but it's one of 99, and at least where I play that isn't enough. Your meta/store/environment may be different, but if a deck doesn't have at least three ways to handle artifacts/enchantments where I am you're dead. It may be different for you where you play.

I think you're light on land, too, especially since you aren't running any ramp or fixing. I'd get up to 35 at least, and get at least a little ramp (Sol Ring, Orzhov Signet would be easy, cheap starts).

Urborg Tomb of Yawgmoth is getting reprinted in M15. Get one, it's great fixing with almost no downsides.

For that matter the old Legends Urborg is decent, too. It's for all intents and purposes a swamp that lets you remove first strike or swamp walk. Is it amazing? Not a bit. Has it made a difference for me more than it's hurt me? Yes. The times I've been glad I could take first strike away from Glissa the Traitor or swamp walk from a zombie deck outweight the times I wish it was a plain swamp (in the event someone plays a Blood Moon or something). Not a huge deal, just something to consider.

I also consider Homeward Path a must-include in a deck, but I play in a place where one guy plays Zendruu, one plays a Kiki-Jiki theft/sacc deck, someone plays a Merieke deck, etc.

Is Evolving Wilds worth running? The land comes into play tapped, so you can seek out whatever you need but not use it for a turn. You could just run a Orzhov Guildgate and have it come into play tapped so you can't use it for a turn but then you have a dual land. IMO thinning one card of 99 isn't better than having the flexibility of a dual given the choice, but that may be personal preference.

Unmake over Murder. Same CMC, but Unmake will exile so it hits Theros gods and prevents graveyard shenanigans.

You should have a few more ways to deal with troublesome enchantments/artifacts. A token deck dropping a Doubling Season or Cathar's Crusade tends to be game over, same with a blue deck dropping an Omniscience or Sharuum deck dropping . . . anything. I'd find room for at least a Return to Dust and maybe a Revoke Existence or Mortify, too.

Nature's Will is a nice way to double your land usage per turn.

IMO find a spot for Wash Out. It breaks backs.

You're going to get hurt bad by enchantments. Chaos Warp is your best option, but it's not budget. Spine of Ish-Sha does the trick and it's budget, but seven mana ain't nothing. Still, IMO you need something or the first person who flops a No Mercy or Propaganda is going to screw you.

Dreadbore is under a buck. That's the same CMC as Hero's Demise without the legendary restriction AND it hits Planeswalkers, though it is Sorcery speed.

Vein Drinker is a great assassin. Vampire Hexmage is a great way to kill a Planeswalker. Stromkirk Captain feels like a must-include.

Cover of Darkness will make 95% of your creatures pretty unblockable.

Blood Tribute is amazing in a vamp tribal deck.

Wooden Stake is flavorful and fun, but wouldn't Gorgon Flail or Gorgon's Head (or the more expensive Basilik Collar) do the same thing and more with less restrictions?

Deathreap Ritual is INSANE in EDH. Find a slot for it (over Dark Prophecy maybe). You won't regret it.

I'm a huge fan of Grim Feast. It turns board wipes into 40 life gains. I've picked up 200+ life over a long game with it before. Exquisite Blood does an amazing job, too.

Bojuka Bog? There are times you absolutely need to empty someone else's graveyard.

Urborg, Tomb of Yawgmoth is getting reprinted in M15. I'd say if the price for it falls below ten (which is should) it becomes a auto-include. It does some mana fixing and protects against Blood Moon and Magus of the Moon which most red players are running.

Abrupt Decay is an amazing card in every format but EDH. There's just too many things it can't hit that you absolutely NEED to get rid of. YMMV there, but I wouldn't run it over Maelstrom Pulse or Beast Within.

I'd rather pay a few more mana for Rise of the Dark Realms and bring all creatures under MY control than let other people get their stuff back.

You're going to want a board wipe or two. I like Black Sun's Zenith and Toxic Deluge because they deal with indestructibles. Plague Wind/In Garruk's Wake are nice one-sided wipes, and Decree of Pain draws cards when you kill stuff.

Grim Feast is an amazing bargain card in EDH, especially in multi-player games. "Wrath of God? That sucks. Guess I'll gain 53 life."

Bramblecrush is the same CMC as Creeping Mold but it hits Planeswalkers, too.

Jace Memory Adept works nice here for self-mill, too.

Wouldn't Flickering Ward do everything Chromatic Armor does and more?

I'd run a few board wipes. You've got multiple ways to make Bruna indestructible and multiple umbras that if placed in the graveyard will come right back onto her seconds later when you attack. A wipe is almost always going to hurt everyone else more than it hurts you. I run 10+ in my Bruna deck and wish I had room for more.

Since Bruna has vigilance, Savor the Moment winds up being 3 mana for an extra card draw and an extra attack phase. It's let me win games by taking out one person, playing it, then killing someone else with the free turn more times than I can count.

theholeyfoley is right, hybrid mana for EDH purposes makes the card have a G/W color identity that makes the card illegal to run in a W/U deck even though he technically has the mana base to cast it. From the official rules:

"Hybrid mana symbols count as both of their component symbols for this purpose, e.g. if a player uses Isamaru, Hound of Konda as a general, he or she can not use Kitchen Finks."

I'd consider finding room for Traumatize. Putting 30-40 cards in your graveyard (half of which are going to be auras) right before your attack phase when they'll be automagically sucked onto Bruna wins games.

IMO find room for Nykthos, Shrine to Nyx. You're going to have plenty of permanents in to make it an absolute house.

Will Karametra procc her passive enough to matter? I'm running one more creature than you and I didn't have much luck with it. Nylea on the other hand has a passive that's always useful, same with Heliod.

Glare of Subdual? I'm not running it at the moment myself, but it's always nice to put those non-attacking enchantresses to work tapping out your opponent's best creatures.

Consider Act of Authority over one of the Seals. It's an exile unlike the Seals, it's permanent unlike O-Ring or Banishing Light, and even if you never use it a second time it's worth to leave it sitting there leaving two mana symbols for devotion, adding enchantments to the count for Yavimaya or Serra Sanctum if you get one, etc.

It isn't the kind of thing that comes up a lot . . . but it's going to come up a lot more now with Marchesa the Black Rose now a thing.

Lurking Predators would be great with that many creatures. In a 4-player game even if everyone just casts one spell per turn it's going to get you 1-2 creatures for free every round absolute worst case.