Had a similar build that I used last week, got an ancient Tasker's and Helm very early. Fun build, don't have to do much, just run around and let the avatars do the work :).
I had Baleful cubed and still looking for an Ancient Heartslaughter, but using the flail that makes heavens fury have 2 extra beams atm. Don't see much value for In-geom as you don't get the full value from it.
Also, on your post you say that the Bombardment isn't good, and yes I am all for boosting damage on the avatars, but I have an ancient Bombardment belt and with LoNs 100% increase per item, bombardments are hitting hard and one shotting elites. Personal preference I guess.
Using the AC Hasteful rune for additional AS on the avatars.
I did switch to the LoN bombardment build which feels much faster for Rifts, still using my Phalanx build for Bounties.