Haven't read any other replies, but only your main post. So my opinion is, Aarti is at fault.
As you mentioned she's has many good qualities. She takes stand for women when their character is attacked , talked sense when her team was splitting up saying it was not exactly orange related fight but the frustration for a long time was coming out, she was also right about Paras when she said he was just doing chance pe dance by doing divide and rule thing, using SidSim fight, above all her loyalty.
But when it comes to loyalty, that's her biggest disadvantage too. She gets too stuck in that aspect. Especially when it comes to Sid, coz he never seem to appreciate her, he even shouts a lot on her naive behaviour many time. She feels offended but then she goes back to him once again.
Sid can't be taking advantage of her, if she doesn't let him to. But the irony is, she lets h walk all over her... Sometimes i feel, he respects his rivals in the show, more than he respects Aarti. And imo, it's only Aarti to be blamed at for letting him do that to her.