Can I update my network profile so that my every account would share same profile as SO. Also my display name is also not changing on Stack Exchange main site but any new account will inherit SO profile.
Yes. In your user page on SO, go to the "accounts" tab. At the bottom there is a button to propagate your StackOverflow profile to all StackExchange accounts.
Also you can sync your profiles by going to the StackExchange, on your profile, and press the link
Sync with oldest profile (Stack Overflow)