CentOS 7 now has the VM console as long as the VM has VNC graphics. You don't need to remove SPICE, you can just add VNC also.
What did you do to be able to see the terminal in Cockpit? When I try I just see "Manual Connection" connection info, and a button to launch Remote Viewer. I do have both SPICE and VNC display added.
When I'm using In-Browser Viewer, I don't get anything.
Oh, it was hidden. When I resized my web browser, it showed the "Password Required" box.
In order for me to see that, I have to resize my web browser every time. If it's maximized, I have to un-maximize it, and then maximize it again, or resize it any way period to get it to show. Weird.
Hmm. I don't have that issue. That's interesting.