I actually thought it was a jest.
Just to put things into perspective, a former colleague of mine ended-up driving Squirrels (or Astars as they call them over the pond) in Canada and I recall him telling me about the training he received for recovery from engine failure while long-lining/load-lifting.
The Squirrel's blade inertia is workable, not as comfortable as the Bells but its ok. He said that from around 100ft. (and in a practice situation over an airfield) they could easily recover by nosing forward, gaining slight momentum and then initiating the flare. What he described as more interesting was the practice scenarios from half the height, ie. 40-50ft. These too were recoverable but required lightning reaction, a slight nosing forward (to simulate moving away from the load and to gain a fraction of momentum) and then straight into a flare/collective cushioned landing.
Now if the Squirrel, which is a relatively heavy helicopter compared to the 280, possessing what I would describe as medium-inertia blades, can pull-off a recovery from the very centre of the dead man's curve then I assure you that a 280 will have no problem maintaining rrpm after an engine failure from five or six thousand feet!
Regarding parachute drops - you don't need to execute a free air hover at 5,000ft. to let the boys out. A slow steady forward speed is more than sufficient (below 20 or so kts your ASI will be unreliable in any case and you might better monitor your speed via GPS) but again, jumpers don't usually ask for a zero forward speed jump and even if they do all you need do is put the Enstrom into a gentle climb and from low speed you will kill off most if not all of your forward airspeed.
However - I have to say that I can think of better helis to use for this purpose but, if works for you!
Overall the 280C is a great helicopter for private flyers and, in general terms, depending on your specific environment, comes with my solid recommendation.
Regarding values, Enstrom themselves may be willing to offer you a guideline and there may be some information in the Helicopter Blue Book if you can get your hands on a copy.