I will openly admit in my early days of aging multiplayer, I did exactly what was described in the initial post. Though in my defence it was only to get away with sorting out the less experienced builders when they botched paths or made incredibly unsightly scenery near one of my rides.
I don't continue that practice anymore of course, but if it was easy for someone as (mostly) honest and morally upstanding as me, it must be for those with nefarious intentions.
I agree that mods and admin should have access to lengthier lists of backlogged actions. My only concern is that if it's based on the current 'last action' feature we have, it would be too vague to decipher what happened. I mean could it not end up looking like:
Last action: Scenery, Scenery, Path, Build Ride, Scenery, Path, Remove Ride?
Whilst it could he possible to distinguish the culprit from this info it could still be a bit problematic if another user happened to also remove a ride and then continue on with other things. Then it's a case of do you as the host believe they players are truthful or know the whole story?
Perhaps if the list of actions had a timestamp on them to distinguish when they happened, it could clear up some of the confusion for those hosts willing to run a ship shape server.
That's my two pence on the matter anyway, I've rambled on enough for one night.