Yes, zypper itself works fine, and both of the operations you suggest have no problems. I can also run the terminal version of yast, but this comes up completely blank - all of the Yast menu trees are missing.
Thanks. That got Yast back, but it is in kind of an odd state - it keeps reporting the same patch updates as available even though I’ve already installed them.
This was a bug in 11.0
I thought it was fixed, but as I recall most users just selected never install. Personally it never affected me as I only updated via software management.