Lost me on Question 3:

If the word "only" indicates that a necessary condition will follow, why is it considered the sufficient condition and not the necessary condition?

The Disney argument provides enough support to funnel the viewer into a specific conclusion based off how the support cancels out other conclusions to the observation.

The Tiger argument provides only one supporting statement, however, the conclusion from the author correlates directly to the cause.

The Trash Bin argument doesn't include other sources that could have tipped over the trash can. It is taking prior experience with the cat and applying that hypothesis to the current situation which leaves the viewer questioning if that was the only conclusion that could be drawn.