Quick thoughts:
Massive endurance useage. Maneuvers is a big culprit here. I'd go with one or two Kinetic Combat mules rather than relying almost entirely on defense toggles to get to the softcap.
At the level of recharge you've got, you can throw out Blaze and Fireball every few seconds. They're going to need more end redux. I usually go with 5 Rags/1 End Rdx and 5 Apocs/1 End Rdx and it makes a huge difference. Fire Breath and Rain of Fire also need end redux too. I'm not sure if the Cardiac Alpha can make up for this, but I'd try to build for endurance sustainability so whatever Alpha you go for is pure bonus.
Benumb needs more accuracy.
Sleet needs way more recharge. Like, ED territory recharge. Endurance reduction helps too. I go with 2 rech/end from the def debuff sets, maybe a def debuff/rech/end and a recharge.
You can drop 2 slots from Tough. I almost never run Tough anyway, your main mitigation comes from your defense. It's wasted endurance and slots for the small benefit it provides.
To get more s/l defense you can put 2 Rectified Reticles in Aim. With your level of recharge, the recharge hit won't be significant. Especially since with Sleet, the main benefit of Aim is the +damage.
Hope that helps 
Support Guides for all Corruptor secondaries and Fortunatas
The Melee Teaming Guide for Melee Mans
The Melee Teaming Guide for Melee Mans
Awesome Thanks!
Yeah Endo is nasty, so might shift that a bit. However - Heat Loss 
Sleet is also perma, in terms of debuff vs rech -- but will lookies at that as well.
Thanks Again...
Issue 24 PPM Calculator // The Great Makeover: The Vindicators
Yes, Heat Loss will help a lot for your endurance. But I wouldn't recommend relying on it for endurance sustainability. If you're always soloing it doesn't matter, but on a team you'll want to use it where it will provide the greatest benefit, not ASAP because you require it to function.
While Sleet is perma, the more you can throw it out the better. Double Sleets ftw. Just to illustrate, if you swap 2 of the Posi Blasts for generic recharges so that you've got maxed recharge in it, Sleet goes from recharging in just under 20 seconds to just over 16. That's a solid few seconds and well worth rejigging your slotting there if you can.
Support Guides for all Corruptor secondaries and Fortunatas
The Melee Teaming Guide for Melee Mans
The Melee Teaming Guide for Melee Mans
One can never have to much Sleet! Silas is a wise sage when it comes to cold. *bows*
Playing around with a few ideas...
Power of Fire with the awesomeness that is Cold Domination...
I usually tend to overlook things...
Issue 24 PPM Calculator // The Great Makeover: The Vindicators