TR deployment near Vmca
Forgive me for not researching the Fokker 100 accident, Green-dot (am on that dail-up connection again); but was the aeroplane airborne, and was its speed close to Vmca?
As I've argued above, even idle reverse would result in loss of control at Vmca. And how long would the Tay or JT8D turbofan take (automatically) to "spool down" after an uncommanded deployment of reverse at rated thrust? One or two seconds? Meanwhile, the aeroplane would be swinging rapidly into sideslip, even once full rudder had been applied. I'm arguing generally, of course, not in relation to any specific accident. And I've no idea what the Vmca is on either the Fokker100 or the MD82.
You have rightly alluded to the difficulty of swift crew recognition; particularly if flight-phase inhibition hides the conventional warning, and even if training has covered the likely reason for a snap-closure of one throttle lever. So, if it should happen close to Vmca, the crew would do very well to avoid a departure. I can only presume from your penultimate paragraph that this was not the case in the Fokker100 accident. As far as the recent MD82 accident is concerned, it seems unlikely that the aircraft would have been light enough to have been anywhere near Vmca if it was airborne at the scheduled speed.
A light take-off or go-around is not necessarily safer than a heavy one. Having said that, the wider adoption of optimised speeds on long runways (in order to use less thrust) means that aircraft are flown near Vmca less often than in the past.
Chris