Kör seems to be driving but does överkörd work in other situations that aren't car related? Eg getting trampled in a mass running race like a marathon you could literally say "He fell and was run over by many people".
And, does the combination of över and körd work to create a new word in other similar situations (we were overrun (överspringd?) by the enemy; the government was overthrown (överkastas?) during the revolution; the boat was overturned (övervände?) by the wave... ?
In a crowd, people get nedtrampade (or nertrampade, there's no difference). Like 'trampled down'.
In some situations overrun can be överkörd. For instance, if you have a strong opinion about something but your boss decides it should be the opposite way, then chefen körde över dig and you blev överkörd. This is pretty strong. A weaker expression is stjälpa, which can sometimes be used when a decision is overturned. This feels more like someone spoiled something or something failed. planerna stjälptes 'the plans were overturned'.
If the government is overthrown, it will be fälld in a peaceful context (like: all other parties voted against it), and störtad if it's violent.
For a boat, stjälpte can also be used, båten stjälpte 'the boat turned over'.
In your third option, hunden kördes över, kördes över is the passive past of the particle verb köra ö'ver, is that correct? But isn't överkörd the past participle of the particle verb and, as such, used as an adjective? So is there a difference between Hunden kördes över. and Hunden blev överkörd.? (I am still having difficulty with particle verbs, past participles)
No. Overrun in English is a synonym of overwhelmed, and pretty much only used in military contexts like being overrun by the enemy (like MatthewDWhite's example here in the discussion thread) or perhaps biological contexts, like native species being overrun by another invasive species. The object being overrun is usually a group, not a single individual.
I agree. I had almost all of them marked for deletion in the next tree back when I was a contributor. I do think there is a need for knowing how to express sadness in various forms - but there's a limit, and some sentences are just downright mean for no real point.