poorwanderingwun,
The data Cessna supplied to me for the C208 go down to 400 or 450m (can't remember, it was a couple of years ago) - and that was with at least equivalent loads to the BN2. Using the same loads as were currently used into the 381m strip with a BN2, extrapolation showed the C208 was at least a feasable option worth pursuing with the manufacturer. If it wasn't for the entrenched anti-SE Turbine lobby.
At the time there were also funds set aside for the extension of the limiting runway by 50 m or so which would further reduce the performance data issue.
As for SET vs. light twins, the available data supports the safety of the SET class as at least equivalent to light twins. I've even seen data - but now can't remember where. I think it was from Oz's CASA - that showed a lesser risk due engine failure in a SET than in a light twin.
To argue that eventually a SET will have a failure & crash is a straw man argument. By the same logic and based on in service demonstrated safety rates, a light twin will also have a failure....and turn turtle & spear in.