Not as much as you think. They can just dredge back a GGT and then cast it along with other dredgers. RiP is a much better/more solid answer vs dredge.
I've liked the Boreal Druid as well for the possible ability to trade with something small, also the attack too. Basically the 1 power all the time is completely relevant! I like your other changes in order to accommodate the EDF. I'll have to look at my mana base.
What is the order of resolving matter reshaper, elder, and sanctum
I'm not 100% on this but since they are all your triggers, you order them how you want, once you receive priority.. #JUDGE!
Probably what I would do is put the Reshaper trigger on first (to resolve last) then the Sanctum so that you have "more targets" to hit with the reshaper trigger.
With a turn 1 Noble Hierarch and a turn 2 Temple you have a turn 2 TKS anyway. If we consider putting something in over another card, I recently heard on this weeks Eh Team that Doug Potter won the Face-to-Face Edmonton Open and he suggested putting in Boreal Druid in place of BoP to help aid the C when facing a Blood Moon. Now I do understand that Blood Moon decks are red and will probably have some form of removal, but it's still worth testing!
Saw this on hareruya mtg today (http://www.hareruyamtg.com/en/k/kD03916W/) featuring Eldritch Evolution into Lavinia of the Tenth and a misers Sigarda, Host of Herons. I really like the idea of evolving a Skyspawner into Lavinia but having Displacer as the only other 3cmc drop, seems hard to get up to her, while keeping the displacer combo in tact. I'm thinking of running Matter Reshaper in place of Displacer. Or is the entire point of having Lavinia so you can blink her and detain everything turn-after-turn? I was more thinking this is an alternative to EDF, but I am probably wrong!
I'm not 100% on this but since they are all your triggers, you order them how you want, once you receive priority.. #JUDGE!
Probably what I would do is put the Reshaper trigger on first (to resolve last) then the Sanctum so that you have "more targets" to hit with the reshaper trigger.
Here is his list, before the Boreal Druid inclusion:
http://manadeprived.com/doug-potter-edmonton-open-champion/
1 Breeding Pool
4 Brushland
4 Cavern of Souls
4 Eldrazi Temple
1 Forest
1 Misty Rainforest
1 Plains
2 Temple Garden
4 Windswept Heath
2 Yavimaya Coast
4 Ancient Stirrings
4 Path to Exile
Creatures
1 Birds of Paradise
4 Drowner of Hope
4 Eldrazi Displacer
4 Eldrazi Skyspawner
4 Noble Hierarch
4 Reality Smasher
3 Thalia, Guardian of Thraben
4 Thought-Knot Seer
1 Engineered Explosives
2 Grafdigger’s Cage
1 Thragtusk
2 Stony Silence
2 Negate
2 Timely Reinforcements
2 Relic of Progenitus
1 Dismember
1 Pithing Needle
1 Gut Shot