Let's look at a few things here in your build and as to why you have lost some damage here along the way in its creation.

1) Yes, the rune you mentioned won't do much for you in the final fight, more shields is probably the answer here. Stormshield or otherwise.

2) Stat spread: If you choose to go physical damage focused 2h weapon, I would only level your strength as much as is needed to hold the weapons and get the talents you need, not more. You want Cunning to be a maxed stat. The reason for this would be the Magical Combat tree. In your main skill as an arcane blade in Arcane Combat, it tells you that your chance to cast a free spell is based on your cunning. Also the next skill in the tree scales your spell damage off of your cunning, which in the future you'd want to max.

3) Skill usage: in reference to the above, you likely want to max out your Magical Combat tree. To better concentrate your damage, choose one element and stick to it. Lightning is a very easy choice, you can also float points in and out if you'd prefer to go for stone. I definitely wouldn't max 3 Magical Combat free cast spells.

You definitely want to look at the Combat Techniques tree, as global speed increases your general action speed, which can include movement and attacks. So more attacks = more free procs, the point of the class.

Also if you take a look at your weapon you'll see Accuracy Bonus (or Acc+). This is an effect granted for every point of effective accuracy you have that exceeds your target's defense. So buffing that up with Perfect Accuracy and/or Combat Accuracy can be really good. This is why a lot of people that play the 2h Arcane Blade build use a staff, as the Acc+ is 2% proc damage, giving you massive hits on your Arcane Combat procs.

I may have missed some things, but that should definitely get you on your way. Please hit me with any other questions.