A fully "Mandraulic" helicopter i.e. one without powered flight controls cannot, by definition, have an autopilot. Any helicopter flown in IMC requires an autopilot. Having trained to fly unstabilised, single engined helicopters in IMC from an early stage in my career and having had to fly an unstabilised twin in a later public transport role (it used to be allowed some twenty years ago), I would not want to do it ever again.
One engine = one power source for electrical equipment. If it stops, you are going downhill and possibly without some of the normal electrical systems, making your life even more difficult.
Accident statistics involving twin engined helicopters operating over congested areas might seem relatively high compared to singles, but a single cannot have an accident over a congested area if it is not allowed to be flown there.