lazernerd

Prophet of Kruphix is banned if you're playing by the normal EDH banlist.

If you want to go all out on the 'creatures can't be countered' theme, these cards might be nice to have: Leyline of Lifeforce, Spellbreaker Behemoth, Vexing Shusher, and Gaea's Herald

Terramorphic Expanse for that double landfall trigger.

I'm not sure burn wants any Fatal Push since it can't do direct damage.

So uhh... have you played any games with this deck?

If you're playing casually and lack removal, Slivers are very challenging to face.

Why 4x Oppressive Rays? Do your opponents creatures worry you that much?

I'd say 60 cards for starters with around a 40% mana base and go from there. It would probably be good dropping some of the 1 of's since you want your list to have some consistency.

If you're looking for a budget creature replacement, Monastery Swiftspear is great. Since this seems to be a casual burn deck, you may also consider Price of Progress as a cheap and effective burn card depending on whether your opponents play a lot of basic lands.

70 cards? What's the gameplan?

I'm not really understanding the creature choices here.

Why are there 138 cards?

Could work, but if your opponent knows you have that potential, they're going to chump block Kiln and Nivix. That's where the +Trample from Temur Battle Rage will really come in handy.

Not sure how well that would work here. The deck's almost mono green, so adding in blue would slow it down a bit. Plus, with cards like Ichorclaw Myr, Rot Wolf, and anything that gives +Trample, you are already prepared for opponents blocking your creatures.

Good idea, there's not a lot of 4+ toughness creatures or first strike in Pauper. I think that would fit nicely.

Definitely add 4x Windswept Heath. Deck looks pretty solid; the only thing I would question is the 4x Selesnya Charm and 3x Sundering Growth. I feel there are better removal spells for Modern than Selesnya Charm (e.g. 4 Path to Exile). You'd probably find 2 more playable, when I tried running with 4 I found them less useful than I'd have hoped. Sundering Growth is also more situational. If you're not going to be playing decks that rely on certain enchantments or artifacts, it won't be of much use.

4x Windswept Heath are perfect for this deck with their release in Khans.

This looks a lot like that mono-white deck in MTG 2014. If you're looking for some really strong white weenies, I'd take a look at Precinct Captain and Mirran Crusader. Some of those cards such as Doomed Traveler, Elder Cathar, Goldnight Commander, and Unruly Mob are not very aggressive cards overall.