Necromancer 2.0

Yes. This is why, instead of having 2 new sets buffing Nova (which is already a top-notch build), you shall be more generic and only buff blood spending.

Alternative proposal :

That was the original idea but it was then abused with perma-Army of the Dead leading to nearly infinite stacks. The stacks must be capped.

Alternative proposal, with damage based on number of skeletons :

Interesting.
But stacking 10 shadows as they are powerful now would be overpowered. Like 10 Necro with Corpse Lance activated… :S

Bone Ringer would then be the old Jesseth Arms.
Why not.

Nope. There is No mechanic where a skill looks back at an item. The direction is always : item X boost skill Y. Loopbacks are not allowed to avoid recursive effects.

Buffing those 3 skills at the same level while they have different damage output is risky.

Alternative suggestion, Bone Spirit as buffing skill :

Agree. See my Bone Spirit suggestion, it handles this problem.