I think zombies only target players as of A17 and also fresh corpses as of A21. There are no AI tasks that set objects or entities other than players as targets for destruction. If workstations, containers, or vehicles, or traps are destroyed by zombies, it is simply bad luck from their random "destroy area" task they sometimes go into when they can't detect any pathway to where the player is. Prior to A17, zombies had an AI task to target doors specifically but that was removed in A17.
As far as screamers, from what I can tell, the source of heat that sets them off simply forms a waypoint for them to travel to much like wandering zombies have a waypoint that they go to. They do not target the heat source to destroy it but simply go there looking for players.