All of the following added to the clarity of the content in kennedy’s inaugural address except
straightforward and simple word choice
the use of pathos
repetition of important ideas
directly addressing the audience with the use of “you”

Pathos Pathos actually is a feeling of sadness which means that it does add to the emotional aspect but not the clarity of content. Simple and straightforward speaking is always the best way to make it clear as well as repeating important ideas so that they stick with the listeners. Finally, addressing the audience as "you" makes it clear who he is speaking to.

the use of pathos

The usage of pathos in Kennedy's inaugural speech is not necessary to clarify the speeches' content. The straightforward and the simple word choice is already a big factor combined with the manner of repeating important ideas and addressing the public using the word "you".