So investing my remaining skill points in accuracy (1H, no shield) was the tipping point for this battle. I backed up to the portal and concentrated on that damn spider. 4 medium health potions under withering assault and it went down. I then jumped through the portal. Wash, Rinse, Repeat. The Fire Elemental went last because my Death Knight's fire spells weren't going to work. Back on the main quest, things are far more doable.
To redo my skills will cost around 2600GP and I have almost 30,000 so this is not an issue. That's a saving grace, that you can reallocate your skills to solve problems without completely committing. As you level up it gets much more expensive however. I only plan to do a "mass overhaul" once, when I get the "Shield+1H" path unlocked.