Gerard -- you forgot about the crap she pulled in PT1970. She nearly killed Quentin with that voodoo doll and the pin, and then there was all the conspiring she did with Hoffman to split Quentin and Maggie apart. ALSO.....that spell she put on Quentin that made him lose his mind and nearly kill himself.
Yes, but that WAS a different Angelique, after all--- she and twin Alexis were personification of the different sides of RT Angelique. After the "good twin" was gone, that's just to show what would have happened if RT Angelique completely turned from her own "good" side (whether to her gain or not.)
It could even be argued that PT Angelique was an example of the popular psychological temporizing which theories were first being publicized in those days---- that she was not entirely to blame for her evil or amorality. Her mother married PT Stokes with her two little girls in tow, and given his own weirdness, maybe there was something beyond trying to gain favor with his stepdaughters.... Simply put, there may well have been some incestuous activity; Angelique responded favorably, Alexis did not, and the latter escaped at the first opportunity.
Then, apparently after her mother's death, the VERY young Angelique got into the sights of the dashing Collins heir---- perhaps that was part of dirty daddy's plans? Then, somehow, along the way, she acquired a too-worshipful housekeeper / personal maid, and ere long, was seducing and teasing all the men within the radius of Collinsport. Then, she died mysteriously, and dirty daddy moved heaven and hell to revive her. OK, a blatant rip-off of "Rebecca" with supernatural BS thrown in, but more explicit.
As to whatever motivated the RT Angelique, it should be noted that there was no mention whatsoever of her activities, whether good or bad, once removed from the combined irritants of Barnabas, the Collins family, and Collinsport. She had been considered "ordinary" in Martinique, and apparently gave satisfaction in her lowly employment, no spells or "nose-twitching" to get chores done, anyway. That, later, she apparently met and married Sky Rumson while living a "normal" life, working as a model, without use of her powers (and even giving them up until spit hit the fan) showed that she was capable of ethical behavior, if not provoked.
And as for Barnabas.... by the time he reconciled with Angelique, he and she were about even in the murder department, and just about every other facet of badness, and zig-zagging with morality and what was still left of their consciences. In real life, maybe that wouldn't happen, but in the context of a soap opera, it made sense (and has been done ad nauseum on soaps ever since...)
L.