Pocohontas, this is a beautifully written post. I absolutely agree with everything you mentioned especially regarding Riddhima's actions today. Her willingness to embrace memories shared by Arman and herself, to face them and realise her evolution from a girl to a woman and to finally reconcile them has, in my opinion, only made her realise what true love really means; that is peace, trust, sharing, acceptance, compassion, strength and all giving. All characteristics of Sid. Perhaps, this will now give her direction and her feelings towards Sid can now come to the surface without guilt or inhibition. This time away from Sid has freed her from pressure and the constant barrage of betrayal she has felt in the past (albeit unsubstantiated on Sid's part, I believe).
Nevertheless, how heart breaking and devastating to watch Sid's hopes and dreams shattering right before his eyes. His eagerness, anticipation and determination to set things right between his wife and give their marriage a chance to flourish have all been massively wiped out. To say "the choice is yours Riddhima" to actually seeing your wife in her ex-lover's arms is another. I can't help but think at that moment if Sid was shot, an ounce of blood would not ooze out. It was just sooooo sad.