I just made a post about magblades in another thread, so I'll link it here as well.

https://forums.elderscrollsonline.com/en/discussion/comment/4909449/#Comment_4909449

Your setup sounds good, as for skills/rotation you can definitely get good numbers using the latest Alcast magblade PVE build. The bars are set up as:

Front - Twisting Path, Resolve, Swallow Soul, Impale, Destro Ulti
Back - Blockade, Cripple, Harness Magicka (use Ele Drain on a dummy), Siphoning Attacks, Soul Harvest Ulti

As for rotation I'll just copy/paste from his page:

Elemental Blockade > Light Attack > Crippling Grasp > Light Attack > Weapon Swap (reapply Siphoning Attacks if needed before you swap). Keep up Twisting Path and use Spectral Bow from Merciless Resolve whenever it is ready. Otherwise keep using Light Attack > Swallow Soul. From 25% and less you want to make sure to keep up all the DoTs but use Impale instead of Swallow Soul.

It's pretty quick to get up over 30k dps with a magblade, especially with your gear. You might want to consider a double fire staff setup without Ilambris since the off balance changes, but that's up to you.