I know about enabling testing cheats, then Ctrl-clicking the moodlets on my own Sims. However, is it possible to erase all/certain moodlets off of a Sim who lives in the town, but whom I don't control?

(I imagine it would be useful for removing moodlets relating to a recent death in the family, or 'betrayed' from being cheated on, from the target Sim. That way, my own Sim can perform friendly/romantic interactions once again to him/her, that under those circumstances would be rejected.)

Any help is appreciated!

I don't know of a stand alone mod for this, but NRaas Master Controller + Cheats can do this. It's under NRaas -> Master Controller -> Intermediate -> Moodlets when clicking on a target sim.

Thank you very much!