You wan't to build for the heavy attack detonation, it'll force slash procs on everything in the radius and clean house. Raw damage, sacrifical mods if you have them, crit chance/damage and heavy wind up. Life strike too if you feel you want the healing.
Slash (and gas) only scale off base damage, crit damage and faction damage. Putting more slash mods on the weapon won't boost it at all, and since the proc is garaunteed you don't need it for the weighting either.
It looks fine on the face of it and should work on steel path, tell me are you letting the glaive detonate on its own or triggering your own detonation? the regular explosion from volatile quick return won't proc the slash as its not a heavy detonation.
You need to trigger it by performing a heavy attack while the glaive is in mid air (remapping heavy attacks to their own key helps, I like to use 'T'), you can also heavy detonate it directly after the detonation triggered by the mod to get the benefit of both explosions.
I'm sorry but it has to be you brother. The glaive prime is one of the strongest weapons in the entire game, and is widely accepted to be the strongest melee weapon. It might need a couple heavy detonations to kill eximus enemies but that's why i throw killing blow+amalgam organ shatter+primed fury on it for rapid throws.
Corrupt charge, primed pressure point, and fever strike, and volatile quick return are all great but you could take one off and only feel a small decrease in viability. Personally, I take off the smite. Doesn't help against acolytes or thrax and its the best spot to throw attack speed on imo.
Do start by changing your build to try and closely match the one higher in the thread. Reflex coil is a dead slot here.