The cool down for Enkindle should be lowered to 60s with the lost of thunder. Enkindle has an insanely long cool down for the amount of damage a 300s cool down on a skill should do an insane amount of damage Summoners should be able to do 33% damage to a bosses health with a 300s cd. Let's say a Summoner on 196dps Enkindle with it's 300s cool down should at least do 6000 damage. Also if the cool down for Enkindle is lowered to 60s it wouldn't be op because Summoners only use it when Rouse and Spur is up.
Blizzard 2 is a useless replacement for thunder it doesn't fit in with the Summoners play style I tried to find a use for it but I ended up taking it out of my rotation and ignoring it.