Don't know if anyone has asked that before, but after I cure Kodlak, can I remove lycanthropy from the rest of the Circle (except Aela, who doesn't want to be cured) without removing it from myself, or do I have to cure myself first before I can cure the rest of the Circle?

Yeah. Read http://www.uesp.net/wiki/Skyrim:Glory_of_the_Dead#Harbinger_of_the_Companions

By the way, this is pretty spoiler heavy. Don't ruin it for others, and use tags and warnings

I did it before the brothers, I have no problems.