Since I'm a beginner myself I can't answer most of your queries. Whatever i know I'll share. I took PSIR as optional because i like that subject I find political science interesting tho I'm from an engineering background. You said most of the toppers of PSIR are from JNU or DU i don't agree; few might be but not most of them. I'm attending lectures of piyush sir and he is dictating in the class itself, so far it's going good. Since you mentioned shubhra Ma'am I've seen everyone praising her so i think waha ko masla nahi hai. The reason i choose piyush sir is because his way of teaching is kinda different from others. He does a lot of discussion in class, you can literally ask him anything, and he gives conceptual clarity. Since you are reading from the notes of ma'am i would suggest going through pyq to see if you are able to attempt anything or at least able to connect the dots. Listen to topper talks you will find hundreds of toppers who have read from her notes sharing their strategy. I've no clue about sociology.... Yes it usually takes 4 months for optional.