It is not necessary to have multiple user accounts if you isolate the environments. For multiple Oracle product installs on the same server I use shell scripts to set the ENV for each one.
Ensure that your current ENV does not have any Oracle Database references - check .bashrc .bash_profile and run: printenv to verify.
Example: database env script
#!/bin/sh
#
# Defining environment variables for Oracle Database.
#
ORACLE_BASE=/u01/app/oracle
export ORACLE_BASE
ORACLE_HOME=$ORACLE_BASE/product/12.1.0/dbhome_1
export ORACLE_HOME
TNS_ADMIN=$ORACLE_HOME/network/admin
export TNS_ADMIN
JAVA_HOME=$ORACLE_HOME/jdk
export JAVA_HOME
LD_LIBRARY_PATH=$ORACLE_HOME/lib:/usr/lib
export LD_LIBRARY_PATH
PATH=$ORACLE_HOME/bin:$ORACLE_HOME/OPatch:$JAVA_HOME/bin:$PATH
export PATH
Source the env script and start listener and database from shell - database needs to be running for the middleware install
Install Java 8 JDK from oracle.com/technology - I download the tar gzip file and extract to /u01/app/oracle/product/jdk8 {better to use a generic name for the folder jdk8 vs the release number as it is easier to upgrade the jdk}
Set ENV for install:
ORACLE_BASE=/u01/app/oracle
export ORACLE_BASE
JAVA_HOME=/u01/app/oracle/product/jdk8
export JAVA_HOME
PATH=$JAVA_HOME/bin:$PATH
export PATH
Source ENV for install in shell
Start middleware infrastructure installation from same shell (this part does not require the config to be run)
Create Repository: cd to middleware infrastructure home/oracle_common/bin
Run ./rcu -> Common Infrastructure Services/Oracle Platform Security Services and prefix
Install FMW (same shell as infrastructure)
Run config.sh
Post Install: may require symlink to be created if an error - cd /usr/lib64 - ln -s libXm.so.4 libXm.so.3
Create shell script to set FMW env
#!/bin/sh
#
# 12c Fusion Middleware Environment
#
ORACLE_HOME=/u01/app/oracle/product/m12.2
export ORACLE_HOME
JAVA_HOME=/u01/app/oracle/product/jdk8
export JAVA_HOME
PATH=$ORACLE_HOME/OPatch:$ORACLE_HOME/wlserver/common/bin:$ORACLE_HOME/oracle_common/common/bin
export PATH
Source the FMW ENV script then cd $ORACLE_HOME and start the processes
I have found that using the shell and environment isolation works well.
The FMW/Infrastructure requires Java 8 - I have run into issues in the past trying to use OpenJDK for FMW - using the Oracle Java 8 JDK seems to work better.
These were my notes for an install on Redhat 7 - should work on Fedora but may require some troubleshooting - sometimes libraries are newer than the version FMW requires or are missing. Not sure if you installed the Repository in your attempts - if not that might have been why the install hangs - it is trying to connect to the database and update the repository tables.
Refer to the Installation guides for more information
hope that helps you.
