startup mount issues with Oracle
Is the environment variable LOCAL set? this will cause sqlplus to connect to a TNS alias instead of directly to the local database instance.  

Your other problem with starting it into mount, you are missing a parameter to oradim -STARTTYPE srvc.  All of the options can be seen by typing oradim /?

to start just the service so that you can manually start to mount use

oradim -start -sid dantest3 -starttype srvc


At this point the database will not be registered with the listener so you will still need to connect without using the listener.