Why the Home Oracle files are rwx rwx r-x. the oracle home should have the permissions rwx r-x r-x.
# chmod -R 755 /home/oracle/*
To switch to an other user, it is recommended to use
# su - oracle
the dash (-) : this is used to load ALL the envirenment of the user oracle.
Don't forget to verify if the .bashrc is executable, if not run:
$ chmod +x ~/.bashrc
I hope this can help you