I'm taking a break atm. My helixes were doing ~1500dmg normally, or MB/ebul'd against a target that takes 1/2 dmg.
I did over 3k helix to a wildskeeper NM Hurkan. It was weather/day/MB/ebul'd. want to say it was 3400 but it's been a while.

I almost never cast T5's. I went around sky 1shotting a lot of elementals for clusters once. I'm not sure, but I want to say I'd do a T4, then find the next & do a T3&T2. Find the 3rd do another T4, 4th would just get helix'd & follow me to the next camp while it died.

I unmerited enlightenment for focalization when delve came out. needed the extra m.acc towards the end of fights a lot. I never moved it back.

low tier nukes/helix: Atinian Staff. (mythic would do better)
high tier nukes/kaustra: I use a Lehbrailg (augmented MAB+29 int+6)