I am creating a video and want the audio to continue playing for about a second after the video fades out. I am going to import this into Premiere and cut to a new video so the second of continuing audio overlaps the new video. The problem is when exported from AE the video continues playing until the end. I can unlink the audio and video in PP and edit the video portion down, though is there some other way of doing this? Almost like fading out to transparency?
Creating the fade to transparency in AE requires that you understand rendering with an alpha channel and locks you into specific timing that is not easy to change. I would just do what you are describing in Premiere.
You can animate transparency in Premiere Pro. These are basic skills. You can also apply a dissolve transition in Premiere Pro and get similar looks. You could also just use a J or L cut - cut the video before or after the audio, and then apply one of the Dissolve transitions available in Premiere Pro. The proper technique depends entirely on the shot. Everything I have talked about is a basic skill covered in the training on the Premiere Pro Product page.