Hi,
first i think it should be LD_ASSUME_KERNEL=2.4.7, and it is only required on oracle version 9.2 and older.
Second, the message you got (ORA-01017) should mean your database is running but your credentials are wrong. Seems that there is another problem while starting or creating the database. Possibly with wrong LD_ASSUME_KERNEL variable the build of the oracle core will not work correctly.
Also, did you check
http://www.puschitz.com? There are plenty of detailed oracle installation descriptions on linux.