Hi Martin,
I have seen customers using Oracle as backend will eventually increase suggested values for parameters like processes, sessions and transactions.
If eventually you will have a very large Oracle db, decide a proper parallel level on your tablespace and use an Enterprise version also a proper processes accordingly.
For memory, use the the default automatic memory management.
We support shared server architecture as mentioned in the doc, but have at least processes > shared_servers +100
Choose proper charset when installing Oracle to avoid unnecessary conversion in the client side, pls consult your dba.