It really depends on your play style, but I'll give you my opinion anyway.
I personally hate cones, so I've always stayed away from the Frost Breath. Imo, a Kin is all about the buffs. I'm too busy keeping everyone SBed and whatnot to really bother having every single Ice attack.
Aim also isn't necessary for a Kin to have.
Bitter Freeze Ray sucks. Get rid of it.
Inertial Reduction is pointless for a Kin to have. Really. Get rid of it.
Increase Density can be extremely helpful. If someone dies on the team, I always hit them with it when they rez in case they don't have a Break Free. It's also a nice place to put some +Def IOs in.
I really don't agree with you taking Hasten so late in your build, but again, that's your play style. Personally, I'm all about the low level SFs and I don't strictly just do the high level ones or just farm, so it's important for me to have it at a low level.
When I first made my Kin I did try Hover, but I learned to hate it. Fast. I think a lot of people feel it's going to keep them safe, but when most mobs have at least one or two enemies that are ranged, it's not going to help. Not to mention moving around in caves can be quite difficult. It didn't take me long to switch to Super Speed and I don't regret it.
I don't agree with your Ancillary/Epic choice, either. I always tend to go with Mace Mastery. The Scorpion Shield is, I believe, one of the only shields that has +Def. The rest are +Resist Damage I think? But don't quote me on that. Also, by taking Web Envelope, you lose the scattering of mobs when you use Ice Storm & Blizzard.
You could have the best damage out there, but my take is that if you don't know how to handle your toon or don't have at least some good defense, you're useless to the team. And for that reason I picked up the Fighting pool to add a bit more defense. You NEED to be alive to be good. Unless of course someone has Vengeance on the team.
Now, as far as your slotting goes...
It is NOT, I repeat NOT, necessary to have ALL of your attacks 6 slotted. You could end up using those extra slots somewhere else.
Don't 6 slot Health. Ever. Really, the most you need in is it 3 slots for a Numina's +Regen/+Rec, Regenerative Tissue: +Regen, and a Miracle: +Rec.
Speed Boost should have about 4 slots in it. I chose parts of the Performance Shifter set.
I cannot stress enough about Transference having 6 slots. Either go with the Performance Shifter set or Efficacy Adaptor set. Your call.
Fulcrum Shift doesn't NEED 6 slots, but I do recommend AT LEAST 4. 2 Accuracy, 2 Recharge. If you can fit in more, then go to 3 Accuracy, 3 Recharge.
The most Combat Jumping needs is a LOTG Global Recharge.
I would also recommend sticking a Stealth IO in your Sprint power. I used to have the pool so I could fit more LOTG Global Recharge in my build, but I dropped it so I could fit Teleportation in. I hated being the 1st or 2nd person to the end of a mission in a TF and having to wait for everyone else, so that has definitely come in handy. So now all I have is a Stealth IO in Sprint and it works just as good.
My apologies that this was like a novel, but I just wanted to be thorough. If you would like to see my Ice/Kin build, please just let me know.
