I have some good news for anybody else with this problem. I managed to push this through the TAC and they looked into things further and found the issue.
Turns out there was something going on with file permissions in the RF Plan installation directory which was preventing the database starting.
The visualrf logs showed the following:
aused by: java.sql.SQLException: cannot create log file at directory C:\Users\Scott\Documents\RF Plans\airwave\data\database\log.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
... 12 more
Caused by: ERROR XSLAQ: cannot create log file at directory C:\Users\Scott\Documents\RF Plans\airwave\data\database\log.
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
015-07-08 12:05:31,261 ERROR Database com.airwave.core.data.DatabaseServiceImpl Database is required startup cannot continue. initiating shutdown
2015-07-08 12:05:31,265 ERROR Event com.airwave.core.EventDispatcherImpl persist threadpool size property
java.io.FileNotFoundException: core.properties (Access is denied)
To resolve this i uninstalled the app, deleted the backup files in the rf plans directory above and then did a clean install. when i opened the program for the first time it asked me to specifiy a directory for the RF plan files to be stored. I placed them in a folder on c:\ and it worked fine!
Hope this saves someone else some hassles as its taken me nearly 3 weeks to get this fixed!