Hi @casabenedetti,
the first two warnings are deprecation warnings according to the update to the new OpenVPN-2.6.x version. A more detailed description are located in here → OpenVPN 2.6 Development version - #3 by ummeegge .
The third error message is old and known and is also correct in terms of the OpenVPN handling according to his configuration. Since OpenVPN drops his privileges to an unprivleged user (nobody) while starting the instance, the process is after a SIGTERM (stopping the process) not capable to execute the deletion of the routes (kernel space), therefor you would need plugins like down-root but the system makes this on itself after a period of time.
Hope this helps. Best,
Erik