I've been playing with a very similar build, and greatly enjoying it:  I did, however, differ in a few respects, but mostly just to see what would happen.  For instance, I'm going to be using a full set of stalhrim light armor once I get Enchanting maxed out, as well as get my Smithing to 100.  I'm also tinkering with Dragonborn Frost in conjunction with Frost Breath (which I opted to get all three Words for early on), for a little something extra.  Been a lot of fun so far, and I would have completely missed out on it, had I not read over this build first.

Okay, so I'm really late to the party, but this is fantastic.  It should also be relatively straightforward to update the roleplay section, should you so wish, but it works well as it is in my opinion.  It's a really great build, and the best way I've seen to make the frost magic aspect of a vampire's armoury very dangerous indeed!  Great thinking.

My only problem is deciding whether to the the Elven Greatsword or the axe or sword.  I love one handed weapons, but the greatsword is so aesthetically pleasing that it's hard not to take it.  I think that the axe or sword combines better with frost magic though, since a one handed Ice Storm or Frost Cloak can be handy during those prolonged combats.

Has your opinion of one-handed vs two-handed as a caster changed?  I noticed your seraphim build uses a two-hander and destruction.  Also your thalmor Nemesis uses a two-hander and magic.  Have you decided that a two-hander is preferential?  If you made the Volkhair all over again, would it look more like an evil seraphim?

Seraphim uses Two-Handed with Destruction because according to Mason, using both hands for spellcasting is best for the Seraphim due to the nature of the Ultimate Atronach. Also, Nemesis has the option for either One-Handed (Silver Sword) or Two-Handed (Ebony Greatsword).

I'm just going off what Mason said above is all, in conjunction with what appears to be a change in preferential playstyle.  Mason said in the post I replied to "...two handed i absolutely loved because of the elven greatsword but i hated swapping it out with my destruction spells".  But swapping greatswords for destruction is a defining attribute of the Seraphim.  On master difficulty, I find I have to dual cast destruction to make it worth the time.  Also skills like "critical charge" for one-handed just really seem lackluster compared to 2H equivalents.  Plus it's still one hot key, whether it's a single weapon or double weapon.  Like I said, I was just curious if he had changed his point-of-view.  

To quote the actual Seraphim build: "Although on the surface their combat style seems more suited to a more traditional spellsword, casting abilities are nearly always best used in synergy with each other and therefore require both hands because the true joy of running a Seraphim is concentration casting." Presumably, this is the reason why he went with Two-Handed for the Seraphim yet went with One-Handed for the Volkihar.

Obviously, only Mason would actually be able to answer your question but he's been on hiatus as of late. That being said, I don't think it was a change in point of view so much as it was a two difference choices that reflected the combat styles of two different builds.

Does anyone know if the ice storm+slow time combo still works with the latest patch? How about unofficial patches? I mean I am not sure if ice storm ticks more than once per enemy if the time is slowed, I am not sure if the DPS of ice storm is also slowed down by the shout.

Best stat spread?

Weakling elf! they ruin everything with their heretics.