However, can I get 2.483 working with my existing license?
Only if you have a 2.460 installation disk, which is not available for download.
error: "CodeMeter or WIBU-KEY runtime system is not installed!" even though it is, and it launches vanilla SB Pro PE.
Which "vanilla" Pro PE?
I tried updating the CodeMeter system like it says for the v2.3xx updates, and then SB Pro PE to go along with it, but that error occurs.
Uninstall everything related to CodeMeter. Maybe you have several parallel versions installed (has happened in the past).
Do it through the "Add/Remove Programs" applet in the System Settings.
Once that no more entires are listed, download the latest CodeMeter runtime
Then do a firmware upgrade. Start the CodeMeter Control Center, click the circular arrow in its main window, then follow the on-screen instructions.
Then try to launch SB Pro PE. If it fails, run the CmDUST program from the CodeMeter program group (/Tools subdirectory). This will, after some command line activity, open a Window with a new file named CmDustResults.log. Send it, along with eventual error messages, to Support@CodeMeter.com (and CC me, if you like, so I can monitor the support process).