I run an Esper variant of mill. A card I have been testing in my SB that has worked very well is Angel's Grace. Its great against aggro, just not against Infect. It can also help against Amulet Combo. It won me a match against Merfolk. Angel's Grace is amazing! Just my 2cents. You should try it! If you don't run white try Darkness. Black fog is nice against creature decks.
I understand that if Sulfur Falls is the only land in your hand it can be a problem. It hasn't been a problem for me which is why I use it. It works and I won so I'm definitely not complaining. Also, what does your meta consist mostly of?
After testing Tormenting Voice by switching it with Thought Scour I haven't looked back. My list is pretty standard as well as the sideboard. I however feel 4 Swan Song is necessary and comes in handy against a lot of the top decks in modern. I won a tournament with the first place prize being a Tarmogoyf beating Affinity in the finals with UR Storm. Here is the list I am currently running.
UR Storm: (60)
Lands: (16)
1 Mountain
2 Misty Rainforest
3 Island
3 Steam Vents
3 Sulfur Falls (I've had no problems with this and feel it's better than Shivan Reef)
4 Scalding Tarn
Creatures: (4)
Goblin Electromancer
Spells: (40)
2 Grapeshot
3 Desperate Ravings
3 Past in Flames
4 Desperate Ritual
4 Gitaxian Probe
4 Manamorphose
4 Pyretic Ritual
4 Pyromancer Ascension
4 Serum Visions
4 Sleight of Hand
4 Tormenting Voice
Sideboard: (15)
2 Echoing Truth
2 Empty the Warrens
3 Blood Moon
4 Lightning Bolt
4 Swan Song
UR Storm: (60)
Lands: (16)
1 Mountain
2 Misty Rainforest
3 Island
3 Steam Vents
3 Sulfur Falls (I've had no problems with this and feel it's better than Shivan Reef)
4 Scalding Tarn
Creatures: (4)
Goblin Electromancer
Spells: (40)
2 Grapeshot
3 Desperate Ravings
3 Past in Flames
4 Desperate Ritual
4 Gitaxian Probe
4 Manamorphose
4 Pyretic Ritual
4 Pyromancer Ascension
4 Serum Visions
4 Sleight of Hand
4 Tormenting Voice
Sideboard: (15)
2 Echoing Truth
2 Empty the Warrens
3 Blood Moon
4 Lightning Bolt
4 Swan Song