Tasks crontab on mediatemple

Hello, I can't seem to make sense of the tasks. I think I have my crontab setup correctly, but wanted to check I'm not doing anything crazy.

Using Plesk, I've added the following settings:

My command reads curl --silent http://beta.roodesign.co.uk/TRIGGER/tasks/tick > /dev/null 2>&1

Which seems to fire, however, it now fires every minute?

So, here's my slew of questions:

• Does this setup look correct?
• Is it going to kill my sever firing every min?
• I'm guessing I then control the timing of each individual task with a call in define() { something like $this->add(5, 'fetchFlickrGalleries');?
• Is there anywhere I can dump the output of php bugs that occur in my task? preferably in the admin.
• Why /tick? shouldn't that be the url of my task?

Sorry, I know some of this is in the docs, but wanted to make sure I wasn't doing anything mental.

Chars!