No, you can't rename categories, only delete them and recreate.

To disable logging, you can edit the debugging.py file (in /opt/FeedingIt if I remember correctly) to add:
level = logging.CRITICAL
just before the line #78:
logging.basicConfig(
Note that the indentation (number of spaces) does matter, and should be on the same level as that line.

And thanks for the suggestion and bug reports. But just to set expectations, I'm fairly unlikely to take the time to fix it at this point.