I think he switched to Energy Recovery to have a bit more defense and because with Spell Twisting you use less at-wills. Whatever, none of them is an important feat, so it's up to you. The feats you chose are not bad (just take 5/5 Chilling Advantage), the problem is that you won't have enough point for Spell Twisting or…
http://nw-forum.perfectworld.com/showthread.php?813401-Community-Control-Wizard-Module-5-Bug-List •Arcane Singularity: Enemies affected by AS are immune to damage from Sudden storm, Shard of Endless Avalanche, and Oppressive force.
My main is a SS but I'd like to try a MoF toon. His build will be Rene+Icy veins, but I have a doubt regarding dailies. Swath of destruction +...? - feated chilling presence - combustive action - critical conflagration
40% is not the cap, it is the minimum advised. The enemies in WoD were easy to test on preview: heralds have 60%, mobs around 35-45% (more or less, I don't remember exactly). Has anyone tested enemies resistances in T1 and T2? EDIT: abaddon writes faster than me :P