The premise of this build, is that you don't have to have super horrible damage just because you are a support healer.
By stacking EAD and DTE wherever doesn't take away from you healing power, and my using competent w/ FlashBang to boost your damage while keeping enemies locked down due to a low 10-11s cooldown. The idea is to Flashbang and focus on an enemy's head.
For the weapon setup, they will also be taking an extra 22% damage due to being out of cover (from blind status). There is also great suppression power, because of dual-220 mag LMGs.
This setup can also work with the Urban MDR (if you're good at using it), for the damage bonuses of 24% EAD and 18% Exotic talent. The benefit of suppression is given up for extra damage (EAD). But since this is primarily a healer, suppression (and thus incoming damage prevention) is my preferred strategy.
Combat medic (or precision) can be swapped for On-The-Move if needed.
If running as a FULL/dedicated healer (no CC), swap out Flashbang for Defibrilator, and Tech Support or Precision for Triage.