Well, if being in tight, confined spaces where lots of people move in an out is bad, then in addition to aircraft, *any* mass transportation job. Aircraft hold more jet fuel than say, a bus or a train, but I don't want to see any of those things crash. When considering vehicles with only one operators, the potential for disaster is lower, however a Yandere driving a bus yelling "NOTICE ME SEMPAI" at 65mph/105kph is a disturbing thought. A Tsundere would, at worst, be cruel to every person she felt attracted too, which translates into poor customer service and workplace relationships. When you are doing complicated or team oriented tasks, this can lead to a catastrophic failure.
Any kind of long term sailing would be bad (is this why there is a Western superstition involving women and boats?). I imagine the worst possible instance of sailing would be operating a nuclear submarine missile sub with a Yandere crew, since if Sempai does not pay attention one or more cities may disappear off the map.
On a more personal note, I would not want Yandere doing any kind of delivery or home service. See 'The Cable Guy' for the male American version of this. Basically they have your home address, game over man. Or if they are the mail woman, your mail. Since everything is electronic now, you can also have a archetypical tech support person, but then its the threat of your shit never working again (or having them cyber stalk you) vs. the mail-woman telling you she's seen you with another woman and she disapproves of the letters you are sending to her...
