Driving school Megane - worth the buy?

Hey everyone, I'm a driving instructor and i've been teaching on a 1.9 dci megane since it was bought for the school. Since they're looking to buy some new cars and sell a few old ones, I was thinking of buying this car and using it as my own personal car cause of the low sale prices driving school cars tend to have. Although the engine's running fine and doesn't eat oil, I'm a little worried because of all the violent stallings and choppy gear changes students do all the time. There's no visible gearbox damage either, it moves into gear smoothly, but you never know when it will fail and I know gearbox repairs are costly. The only thing running bad at the moment are the engine mounts. I want to know what are the chances of a gearbox / other transmission / engine parts failure any time soon. To put matters into perspective, here's what the car gets on a regular basis: sudden clutch engagement from stand still with lots of bogging and shuddering, second gear engagement is again pretty bad and abrupt; I've even had one student who downshifted from 3rd to second a couple of times and abruptly released the clutch into a loud bang that made me die a little inside:). What's your opinion on this? The car is a 6+1 speed manual and 80k miles.