Note: At the End of Act 1 (around Level 11) with Spirit Mastery and Valiant Aura: Spirit Bolt with Spirit Strike crits are 400ish, end of Act 2 600ish and end game 800ish (excluding disorient crits). This is 2nd run through details and notes are for reference. This is reference for those looking for an example and based mostly on my personal preferences. Attributes are place in Magic, then Dexterity (for +critical chance) and Cunning (for +critical damage).
Damage: 41 spirit damage (56 per second) +3 willpower +15% spirit damage 2.5% chance to infect with Walking Bomb
Note: I have no DLCs and do not use gold/xp exploits.
Note: If I am lucky with the random generated stat drops stack +X% spirit damage, +X% critical chance, +X attack and +X% critical damage items while I wait for certain equipment. I use Spiral Eye armor set, Armor of the Overseer and Mantle of the Champion (mage) items in between as well. In this run through I was very lucky and middle/end of Act 1 I got Charged Circle Robes with +13% spirit damage, bonus for it being a nice looking chest piece since I am very picky about how my character looks :P
I know best style of Arcane Warrior uses a sword and board. However, I have customized my Mage as dual wielding caster using multiple poisons and find it overpowered. Skill priority: Max Coercion, 2 points Combat Training, 1 point Poison Making, then Max out on Combat Training, lastly Survival (2-4) points and 1 point Stealing to open questline (I usually add this while still putting points in Survival or before hand). Crowd Control with spells that weapons don't have to be sheathed (Check out Arcane Warrior Spellcasting) is a plus. I do feel like a Caster Rogue but found this much more enjoyable than a regular Rogue or regular Mage.
After leveling several different types/styles of this specialization this is what I found to be optimal with chance of personal preference/customization and party flexibility. I don't want to be told how to play a cookie cutter spec and play style and I don't expect anyone else to either. These are recommendations and things I researched on the specialization.
Even with the intent to have an Arcane Warrior, keep mind you do still start out as just a mage and play as one for a while and wait till you have key spells you plan to use and the Specialization point ready, for when the time comes to use the items/spells. Start off by reading and noticing what level each Arcane Warrior Spells are available, then look over all the Spells and then make reference to Arcane Warrior Spellcasting if you plan to wield anything besides the staff this is something to pay attention to. Drawing and sheathing weapons is time consuming and unless it is a very good spell I'd refrain to as few sheathed weapon spells as you can or you could be juggling your weapons quite a bit or stick to staff. As you level to get to your Specialization keep in mind the spells you want to use once you can go Arcane Warrior.
Once spec'ed Combat Magic, spells and combinations, supporter, defender, debilitator, damager or healer or any custom tactics and role can be sorted and set up. Then you can work on the gear, once you decide your game style and gear/equip type you can start picking up or purchasing if you haven't already.
Setting up your party the more mages the better, custom spec'ing to created and optimal party. To get the idea have a Defender/Damager mage and a Healer/Supporter mage or Debilitator/Damage mage and Damager/Healer mage in your party, are just some suggestions. Having your Arcane Warrior team up with a another Arcane Warrior can work out well.
Battlemage - Awakening only, Sustained damaging abilities and Hand of Winter, seem like the greater threat and damage missing for a nuking or tank mage. I believe this combination was to be intentional, since 'Arcane Warrior' could be lightly considered a 'Battlemage' even before this was a specialization.
Blood Mage, Those with mana troubles some use Blood Magic to work out that problem. Not recommended for tanking since Blood Magic healing debuff, taking damage and casting can deplete your health fast. However, balancing by activating and deactivating Blood Magic, if up for the complexity can work.
Keeper - Awakening only, This is a good balanced specialization with crowd control, shield and health regeneration for an Tank, Debilitator or Supporter/Healer.
Shapeshifter, As a AW Defender, can use Shapeshifting for armor but not for attack since Combat Magic cannot be active while in shapeshift form. One strategy is for when mana is depleted and threat is high taking Bear Shape and let your damagers finish the job, while you take it.
Spirit Healer, As second or back up healer for party support or one you may want to Solo. If you have high fatigue you may want to heal sparingly, and in the event of having your main healer die, you can turn off you Combat Magic and focus healing or just top everyone off and/or revive your healer.
Probably the most overpowered class Specialization in the game; fully geared and comfortable with your game play, spells and party, feels like you're cheating.
Equipping Clothing and/or Light Armor/Medium Armor dodge/resistance gear, Weapons, accessories and equipping Hale/Dweomer Runes, creating more melee caster or fatigue managing caster for play styles. Ranging stats +30% - 72% Spell Resistance, +16% - 36% Chance to Dodge Attacks, gearing and rune enchanting several slight varieties to personal preference. Some examples:
Armor: 1.25 Fatigue: 0.52% +1 armor +10% chance to dodge attacks +10% Chance to avoid missile attacks
Reaper's VestmentsReaper's VestmentsClothing Reaper was an apostate mage who evaded the templars for many years before being captured. Part villain, part folk hero, it is said he led a charmed life avoiding dangers that would have killed lesser men.
+6 constitution +20% fire resistance +16% spell resistance +10% chance to dodge attacks +12 armor
First Enchanter's CowlFirst Enchanter's CowlCloth helmet This has an odd smell... like sulfur and gravy.
+4% spell resistance +10% chance to dodge attacks
The SpellwardThe SpellwardAmulet Templars assigned to hunt the most dangerous apostates and blood mages treasured this amulet above all else. The circumstances through which it left Chantry control are better left unconsidered.
+5 willpower +8 health regeneration while exploring +30% spell resistance +10% chance to dodge attacks +6 defense against missiles
Andruil's BlessingAndruil's BlessingBelt Belts of this type, crafted by ancient elven keepers, were given to a clan's honored allies. Although the fine engravings are faded from age and use, the enchantments remain strong to this day.
+2 to all attributes +20% nature resistance +1/+2 mana regeneration in combat +1/+2 stamina regeneration in combat +10 physical resistance
Key to the CityKey to the CityRing Key to the city of Orzammar: A traditional diplomatic boon, granted by the Assembly, in acknowledgement of the bearer's understanding of the complex dwarven social weave.
+2 to all attributes +4% spell resistance +10% to healing effects received and/or
LifegiverLifegiverRing The dark arts of a powerful blood mage forged this ring. Despite its unsavory origin, the ring's power has made it a favorite of many nobles and heroes over the centuries. Some say its abilities come at a price, but if true, that price is not apparent.
+10 constitution +3/+6 health regeneration in combat +10 health regeneration while exploring +3 armor +20% to healing effects received
As for Melee Weapons Spellweaver is the best and only class specific item for Arcane Warriors though there are other weapons to tide you over till you get it or you stick to your staff until better weapons become available to you and of course if you want to be still use staves you can easily do so as well, and choose according to your spell build (ie. cold spells use +X% cold damage spells). Choices of melee weapons: Sword and Board (being the most popular choice), Dual Wield (best daggers are 26-30 dexterity till able to equip) and Two Handers (being the least popular choice). Some examples:
Note: Considering the balancing of mana reserve and high fatigue, when using melee weapons you might want to try having one point in Poison-Making, for crowd control: draining mana/stamina, chance on stunning and/or a penalty to movement speed on top of extra damage with no strain on your mana pool for your Arcane Warrior.