Code:
1/ Can I remove the listener.log (as you can you with the alert.SID.log) and it would generate a new one once needed?
YES.

Code:
2/ should I re-direct the listener log location from within listener.ora file? Which is the better option. I would prfer the first but what do you think?
Depends on situation.
You can always change the log file directory by setting
LOG_DIRECTORY in the listener.ora file.
You can also change the LOG_DIRECTORY value dynamically using lsnrctl utility.
Alway prefer LSNRCTL reload ( where ever applicable ) - this will not down the listener.

Jr.