Do আপনি think I should un-fan all those people on this site who never fanned me back?

Honestly, like আপনি said, that's up to you. Personally, I wouldn't but, like, that's because I'm too lazy to do so and don't really see the point. I don't really unfan people unless they persistently bother me.

Frankly I've always seen fanning as less of a friend thing and আরো of an, 'I like the content that আপনি post/I share the same interests as you' type thing.

It depends on how আপনি look at it. If আপনি think of becoming someone's অনুরাগী as "friending" them, then maybe আপনি wouldn't want to remain their অনুরাগী if they didn't reciprocate. But others (like myself) অনুরাগী people because they like their contributions অথবা agree with some of the মতামত they've made, so it doesn't matter if they don't অনুরাগী me back অথবা even if they're no longer active here.

I personally wouldn't bother as it would take up time I don't care to use. If আপনি feel strongly about removing someone who didn't অনুরাগী আপনি back then be my guest. It doesn't matter to me in the long run. So I am in a similar নৌকা as Flicker.

It's up to you. I wouldn't do it as it's a waste of time and energy. I never understood the point অথবা value of adding as a অনুরাগী here. It's not like বন্ধু get extra access to privacy অথবা something. So, I just অনুরাগী people if I have enough respect for them. And if someone adds me first, I usually add them back as an act of formality অথবা common courtesy. The whole add as a অনুরাগী thing is nothing but a boost of ego here অথবা sense of security/insecurity. The blocking system is somewhat useless too.