In addition to the straightforward uses of Imp (trashing expensive things for free and trashing operations), Imp can be used as a poor man's Film Critic. Against, for example, Obokata Protocol, you can trash it in the remote and pick it up later in Archives when you are ready for it. Against The Future Perfect, you can play the Psi game, lose, then trash it (or win and steal.) Against Punitive Counterstrike, you can delay the steal by trashing the agenda, waiting until you can beat the following trace or just straight win from points first. You can trash any agenda because the window to trash occurs before the window to steal.
Imp does not, however, avoid any on-access punishment just as trashing an ambush does not prevent its negative effects. Casting Call/TGTBT will still tag you, Quantum Predictive Model will still jump into the Corp's score area if you're tagged, City Works Project will still do meat damage, and Explode-a-palooza will still give the Corp credits, whereas Film Critic avoids these effects. And you still have to steal the agenda from Archives to take its points (assuming the Corp doesn't recur it back with Preemptive Action or Archived Memories.)