Hiya! You're new to I-F, so I dont think you know all the rules too well, no probs!
Firstly, on I-F we never EVER compare actor/actresses, because it may offend some members, and I-F is a family. We dont want to hurt anyone!
I can see you're an SA fan, so am I! I adore her, but please lets not judge on looks now. Riddhi is beautiful- not boring. I understand if you dont like her character "Kiran" - I dont either, infact I HATE her! But Nayak personally is cute! Both she and SA are beautiful people in their own ways.
But I agree, Shubhangi will always be the one, the only Kasturi. But she hasnt left as in yet, so dont feel to down! For you never know what could happen!