The following things should be available before the BB services are started:
- network services up and running
- database reachable
- global catalog server reachable
- exchange reachable
- external RIM server reachable
- AD reachable
Can you check through the system event log after the startup errors. What services are starting after the ID 7000 errors?
Does the Attachment service start? It is the only service that is not started as the BESAdmin user.
Can you also look in the security event log to find out why the logon errors happen.