Healing aura not really needed. I placed it near other auras and move it with Jester on top of a lamp post on top of the roof during later waves but it can also stay down near other auras and it will reach some rooftops.
Waves:
Upgrade buff beams first, then max everything as able.
During last wave going to the roof on marker 5 is a good spot to fight the boss.
This requires going west then north of marker 4 and walk on some suspended wires.