As I continue to make sense of the wiring in home, I have come across some shared neutral configurations. In one, I find two breakers that have been connected to one NM-3 line i.e. black and red are each connected to a separate breaker (on the same side of the box.) As I understand from here and other references, this is OK but it should be on a 'split-phase double breaker'.
First question: Am I right that this configuration is incorrect and should be fixed?
Second question: This suggests that these configurations are problematic for AFCI installations. I want to upgrade my breakers to AFCI. Will this kind of thing be an issue?
Lastly, for anyone so inclined, I have a Cutler-Hammer CH style board. If this needs to be fixed, which breakers would be acceptable?