Is there an easy way to swap out a graphic, video or text that is already in the timeline so that any effects and key framing can be applied to a new item the same way that it was previously Applied?
This is basic AE that everybody should know. If you type replace footage in the search help field at the top of AE will get a step-by-step. Just because it's the Fourth of July I'll give it to you here. Select the layer in the timeline you want to replace. Select the new replacement footage in the project panel. Hold down the alt/option key and drag the replacement footage from the project panel to the timeline.
Because text layers do not show up in the project panel, you cannot replace footage with text. You can however put a text layer in new comp and then alt/option drag that new comp into the timeline.