Hi Hendrik,
thanks for the reporting. I am the developer of the R package, and now that I have write access I can finally also support via the forum.
Regarding the “error” statement on list_jobs, this is rather intentional. The job list shall simply provide an overview about the status each of your job are in. The log functionality Jeroen is referring to exists also for R - at least in the state I left it in since end of the H2020 project. log_job would be the function you are looking for. Usually it prints updates to the console unless you terminate it or you don’t get new lines for a certain amount of time.
I mentioned that the function was developed using openEO API v1.0.0, so it might not work propely with a newer version. That will be something I’m going to look into, when I catch up on the API changes.