Hi,
Sorry for the issues - this is still highly experimental !
Clearly some paths are not set correctly as you appear to have the file there.
I think this may be a clue:
No rocketchat service. You may need smeserver-rocketchat installed
Is this on a test machine and are you able to try a few things for me ?
I *think* the issue is due to setting up SCL paths so that they are found during the rocketchat install. I may need to add a couple of extra script lines for an initial install.
I think we need smeserver-rocketchat installed first, but if we reboot to set the DB configs and paths it will complain that rocketchat files are not there at startup.
If we install rocketchat itself first we get the errors that you have seen. All a bit chicken and egg

For now, try doing post-upgrade/reboot. Then try manually doing:
npm install
npm install -g forever
Then you can try
service rocketchat restart
and see what happens (note it can take a while to get itself going - monitor /var/log/rocketchat/log)
I know once you have it running the rocketchat RPM seems to upgrade OK - it is just the initial install that is the issue.
As another test, could you try installing smeserver-rocketchat first, enable it, reboot, ignore any errors (though I would like to see them) and then install rocketchat itself ?
B. Rgds
John