It is mentioned on this site that Torah study is not dependent on time as opposed to Tefillin, for example. Am I right that Torah is not to be studied on Yom Kippur? If so, would this then not make it time dependent?

There is no prohibition to learn on Yom Kippur. There is a prohibition to learn most things on Tishah B'av since torah studying is gladdening; yet one can still learn the sad parts of torah.