Which backup files are needed for a successful restore?
The included backup.bat (windows) or backup.sh (all other platforms) script found under $ORACLE_HOME/config/scripts will do the following:


Check that the user running the script is in the DBA or DBOPER system groups
Check that the database is in archivelog mode and have the FAST_RECOVERY_AREA parameter configured. 
Back up the database to the fast recovery area under XE/backupset (online/warm backup using RMAN)
Create a pfile as $ORACLE_HOME/XE/dbs/spfile2init.ora
Autobackup control file and SPFILE to the fast recovery area under XE/autobackup/
Switch to the next online redo log file, letting the current one be archived
Create a log of the backup operation, in the user's home directory


The archive logs are already located in the fast recovery area under XE/archivelog

Note that the PFILE is created in the oracle home, but it is not required to restore the database, not even to a new server. Everything you do need is located in the Fast Recovery Area.

That's not to say that it's not a good idea to additionally back up the oracle home.