Time Machine Terminal Preferences?

I have two issues with Time Machine.

1. 2 hourly backups is too frequent but there is no way to change this in the preferences (10.6.8).

2. Occasionally my back up disc falls off FW and I don't notice. Time Machine waits until 10days have passed before informing me 'It has been 10 days since the last backup'. This is too long, but again there is no means to change this in the preferences.

So, is there a means of setting these parameters in the Terminal?

If so, pointers in the right direction would be helpful.

I'm not a Terminal neophyte but neither am I a power user.