Nice build ! A few tips on what I tried (I have an Ele and a CryoKino3) :
- Magic Shield for an INT tend to deplete your SP and not even protect you that much
- Lethargy is mostly take for the attributes, and it comes only with Wiz2 and 3, but if you think you’re gonna use it, take it
- Energy Bolt is really meh : you can level up to Elementalist only with AA, and then, it has no more damage
- I try Freezing Sphere and the skill is disappointing (low damage, no multi-hit and no freeze), so I would advise you to put the point in Storm Dust who has really nice damage
- Hail has a big aoe, so you don’t need to gather the enemies for it (but you can Magnetic Force + Ice Pike to froze them and cast Hail without interruption, that also works with PP and Electrocute)
- Raise is really useful as a CC, and I would advise at least one point, it can be useful for example to setup Ice Wall (without Surespell, it’s really frustrating to interrupted)
- Not sure of this one, but if you use Enchant Lightning, it changes PP and GP to Lightning instead of Psycho, which means it doesn’t work with Stone Curse anymore ?
That’s a few things I can think about, but feel free to do what you want, that’s your build 
For bosses, you have one big combo, Ice Wall + PP (you can use GP if I remember well, it just doesn’t work as well), but if you’re alone, you will be interrupted a lot before Kino3 Hail and Storm Dust provides good damage on an immobile boss, Heavy Gravity and Electrocute (especially if there is traps) a bit too, and you can then use your Lightning AA to complete your damage
I’m not sure for endgame viable, I’m not really experimented in that for now, but it seems you can do nearly everything with a godly weapon 
