Ah, leave it to an old fart to answer the questions...
Patrick, one of the endearing things about aviation is that there is precious little standardization. It can be quite confusing.
Bell 206's come with one red anti-collision light on top of the vertical fin. Over the years, many operators replaced the dim red lens with a more modern (and brighter) clear lens from Whelen, but one day in the 1990's the FAA had a cow and made us change them all back to red since that is what the ship was originally certified with. Lots of common sense at work there, right.
The switch for the anti-collision/strobe and position lights are just adjacent to the instrument light rheostate on the overhead. Many, many 206's have those two switches and only those two.
However, some operators added additional strobe lights that were not required by the FAA. These lights were either in the form of "wingtip" strobes on the end of the horizontal stab, or a single white strobe on the engine or oil cooler cowlings, or perhaps in the area under the baggage compartment. These additional strobes required a separate switch, which was usually put...somewhere up there on the overhead...most often in a blank or unused hole. (Often the same situation when avionics master switches were added.)
But again, there is no rhyme or reason for the placement of all switches in most helicopters. The conscientious pilot will suss out their locations and uses prior to takeoff on the first flight in the new machine, or shortly afterward in any case.
As for the heater...in the bad old days, Jetbangers used to come with a device known as The Dreaded Janitrol Heater. This was a combustion heater designed to run on avgas. It was a cantakerous beasty, and did not like running on pure jet fuel. Ergo, we often mixed up to 1/3 avgas per tankful. The heater switch was a three-position deal. Aft was "Vent", center was "Off", and forward was "Run" (or "On", I forget). There was a little pushbutton right next to the switch that fired a spark plug to ignite the fuel and get the thing producing heat. This spark plug would routinely foul (jet fuel being extremely oily, you know).
The procedure was that as you made your descent for landing and while you still had good airflow through the heater, you would throw the switch to the "Vent" position to allow it to cool properly. If you forgot, and left the heater on all the way down to landing and then switched to "Vent", the igniter plug would invariably foul and you'd never get the heater lit again that day. The mechys loved cleaning Janitrol plugs that dumbass pilots allowed to get fouled. I seem to recall that running the temperature control down to "Min" helped a bit too, but who even thinks about that when you're freezing your tootsies off? (No heater ever made puts enough hot air up into the footwell of a 206, thank you very much. Bell might as well have mounted those pedals out in the airstream.)
It is suspected that a Janitrol heater was the source of the fire that brought down the DC-3 that was carrying 1950/60's popstar Ricky Nelson and his band. How that heater ever got certified for use in aircraft, I'll never know.