In my opinion, it's optional, eopk maintains a cache of packages downloaded in any installation/update for later use in installations of the same version of the package, I don't know when it's deleted (maybe in /tmp? ) , journal control keeps a journal of every activity/message of the system, it's useful for troubleshooting some errors, but it could grow to Gigabytes in the long run, honestly you'll never notice it, but you can clean it to save some space in your hhd/ssd, with browser history, I never delete it, because I may use it or not, but you can delete it anyway, that kind of maintenance I rarely do it because it's not necessary, just in case it generate some trouble to me, from what I read long time ago, I can't remember were, you can run a linux system for years without that kind of maintenance and it would be just fine.
