Changed DNS server, now can’t connect to internet on Safari, Chrome or App Store

You did eventing right except for one step.

Making new account.

Quit Google Chrome completely.

Go to the Go menu > Go to Folder.

Enter the following directories in the text field, then press Go. ~/Library/Application Support/Google/Chrome/

Locate the folder called "Default" in the directory window that opens and rename it as "Backup default."

Try opening Google Chrome again. A new "Default" folder is automatically created as you start using the browser.

Alternatively you can "teach" your browser.

That is done by adding the :80 to the web address.

Example www.myseite.com:80

Also run the netstat -a -p tcp to see if https (443) are open)

Last not least, turn off the experimental "Built-in Asynchronous DNS" is Disabled in chrome://flags/

For such problem one more option is there where you can check your DNS settings. To fix that problem, open the Network pane of System Preferences and select your network connection in the list on the left. Click Advanced followed by DNS.

In the DNS Servers field, you should see one or more IP addresses. If those addresses are enabled (black, as opposed to gray), select each one in turn and click the minus-sign (-) button. Then, regardless of whether there are already addresses there in gray, click the plus-sign (+) button and enter 208.67.222.220; repeat with 208.67.222.222.

Some more Ipv4 and Ipv6 addresses are given at computerknow.org, you may see there.