Certificate has been added, Seems to capture fine with Firefox but
nothing else for example ping in bash is not captured. I believe Chrome
uses system proxy. Thoughts?
Fiddler Everywhere intercepts only web traffic that goes through the HTTP & HTTPS protocols. The ping utility probably uses ICMP and Fiddler Everywhere won't capture those packets (the ICMP packets are from different layer and not part of the TCP ports).
As for Google Chrome- indeed by default it should be using the system proxy and Fiddler is able to capture its traffic. Make sure that there are no custom proxy settings for Chrome and once the FE client is set and the trust certificate is added, restart both and try to capture a session.