As far as ulamog goes this is my feeling on him (and i say this because i actually have one but i choose not to use it);
Ulamog, the ceaseless hunger is a LEGENDARY creature that you would normally tailor your around as its own deck focus. If you add ulamog to this deck then it would most likely throw off the flow of the deck because you're potentially tapping yourself out to get this behemoth of a creature on to the board. Now I'm not saying you can not use it because its effect works every time it ATTACKS and not when it DEALS DAMAGE so that is an upside but really It would be best used in an all eldrazi deck. My own negativity towards him being in this deck is that all the colors being made are being put towards a colorless creature. If you do choose to play him then make sure you have plenty of
dispel,
cancel and maybe even some rashaka's disdain to make getting him on the board easier. Also if you played ulamog with
alpha authority then he'd have hexproof and all he would need at that point would be to have trample. By that point the game would probably be over simply due to damage. I'm not going to say "don't use that card", what i'm going to say is "if you ARE going to use that card, make sure that it doesn't slow down or put too much strain on the deck itself". Last thing you need is a strong high drop creature in your hand and not be able to play it because your mana ramp creatures are getting blown away early game.
Also referring to the rest in piece that actually would make a good combo in this deck. Play at least 3 copies of
elixir of immortality, that way you can have a a constant elixir loop going as long as you are playing. Adding cards like
drake familiar,
auramancer,
griffin dreamfinder and other creatures that utilize the use of such enchantments can work in your favor. Honestly as far as exiling goes the methods that i most prefer are either; a)
exile straight from the deck, this is where ulamog and other eldrazi with the ingest effect would be helpful, or b) drop cards from the deck to the graveyard and then
exile at once. Playing cards like
tome scour,
mind sculpt,
dreadwaters and maybe even trepnation blade on a flying
shriekgeist would be
dangerous as far as milling with creatures goes. If you wanted to you can place greater emphases on the NO HAND LIMIT aspect of the deck and play creatures like kruphix, the
prophet of kruphix, strumgeist,
divination,
brilliant spectrum, and
graceful adept would aid you in this process. Also if you played
howlgeist and then played
empyrial armor or
righteous authority then you'd have a
dangerous combo on your hands, even more so then ulamog. For life gain in this process
phosphorescent feast and
presence of the wise would suit this deck well. How does this sound to you so far?