What I've seen in your attached doc is an ISPF panel. Please remember that ISPF panels have nothing to do with REXX. You may display panels using any supported language.
To prevent the "abend" screen", use the service "CONTROL ERRORS RETURN" in the invoking dialog (yes, it might be REXX).
Also, as already explained many times in this forum, ISPF uses an internal buffer whenever you re-display a panel, in order to save on resources. If you change a panel and want to display the updated version, run it under TEST mode first (this is also well explained in the fine manual).