The answer may well be in the logs. Below the logs directory of your chosen domain are a number of log files including "server.log" which will show at least installation problems, "icat.log" which is the log of icat operations and there should also be log files from the authentication plugins.
Any JPA supported system should work - which means almost any RDBMS. If you find exceptions please let us know.
The schema is created automatically when the icat ear file is deployed. This works fine if no tables exist. If tables do exist it will try to create them and report an error for each table. If any table exists and has the wrong structure, it will not be replaced or updated, and ICAT will not work properly.