IDEA encryption

[Ben Holiday <ncognito@gate.net>]

The copy of the source for idea (unix) that I have specify's a user key 
length of 8 bytes, but allows this to be increased to something larger. 
Will increasing the user keylength improve the overall security? 

Also, is it worth hashing the user key first, then using the hashed key 
as the key for encryption and decryption? Or am I wasting my time? 

Last thing -- how secure is unix "rm"?  If something is rm'd, is it 
really really gone? 

Thnks..