So I thought of this build today: basically a spellsword that doesn't use Destruction magic. It'd use all other schools, plus Smithing and One-Handed. There's always a couple of kinks that I couldn't get worked out as well as a few general things.

Would it be viable on Master?
What race would be the best suited? I'm stuck between a Breton and Altmer
What side of the Smithing tree would be the best?
What armor should be worn until Mage Armor is perked?
What order should things be perked? I've had too many builds where the main damage dealer is hardly perked.

If anyone had anything to add, please feel free .

Sure. I've got a two-handed battlemage who use conjured creatures and illusions as distractions, alteration as main defense, I also use poisons. I perked Restoration for Vampire Necromage because it extends my Conjuration durations and Alteration Armor durations.

I picked a Nord for RP purposes, but I would pick Altmer due to the 50 Magicka buff; Breton is useless in the long run because of Alteration perks and Lord Stone.

Light armor side would save you perks, but I've always liked the look of a flaming Daedric Armor on a huge Altmer. Heavy side have a perk that would prevent you from getting shouted away by Draugr... But honestly, a functional Spellsword should be quick on his/her feet.

On the order of which to perk first... I would just go along with it for now and see which perks fit your current situation. Get a companion, and If you're careful, you won't get hit much because your conjured creatures and companion will be your vanguards as you quickly destroy your enemies when they're busy.

Also, get Unrelenting Force as soon as possible. Don't worry about the Dragons, your conjured creatures and companions can keep them busy enough while you take care of them.

PS: I personally like going two-handed for this built because you can blitz your distracted enemies more efficiently with two-handed.

1.Yes,I did it.
2.I did it with a Bosmer but of your given choices I'd say Breton
3.Light Armor..side
4.I wore a Modded one,But of the vanilla armours I'd look at Elven or Glass.
5.If you like to get close I'd say get one handed first and then go to Conjuration,Restoration and Illusion(these are the most useful in combat),You can keep using armor till you get the Alteration perks.

I have a spellsword build that uses Archery for distance and then One-Handed and Spell for up close.

Usually I have a Restoration or Conjuration spell charged in my off hand. Rarely use Destruction.

I use light armor for stealth purposes. However, I use both side of the Smithing tree so I can get access to Stalhrim (need Ebony perk).

Totally viable build.

If you aren't using Destruction as your ranged kill skill, I strongly recommend using Archery.