Question: suppose I have 2 servers, both with WHM/CPanel installed (A and B). Is it possible to manage server B through servers A WHM? Or will I need to use each servers WHM for management (WHM A to manage A, WHM B to manage B)?
You would need a third party product to do that, such as WHM Autopilot or one of the other commercial solutions out there. The only thing that can be done centrally on a bunch of cPanel servers is DNS.