Audio tracks and video length

[BG Davis]

I'm trying to figure out how to use the audio tracks.
Issue #1
I added music to two tracks (1 and 2).  Track 2 is longer than track one.
The objective was to have track 1 play to its end point, then have track 2 become audible at that point (part way through) and play to its end point.
Is there a way to make this happen?

Issue #2
If the audio track is longer than the video, is there a way to save the file so that the audio plays to its end point?
The Avidemux tutorial* implies that this is possible: "some video players will only play video for the duration of video track, so if you want the whole audio to be played [the video needs to be at least as long as the audio]"
Notice this says "some" video players.  But I can't even get Avidemux to continue after the end of the video, even though the audio has not played all the way to its end point.

*http://www.avidemux.org/admWiki/doku.php?id=tutorial:create_video_from_still_image_and_from_audio_file

[eumagga0x2a]

I added music to two tracks (1 and 2).  Track 2 is longer than track one.
The objective was to have track 1 play to its end point, then have track 2 become audible at that point (part way through) and play to its end point.
Is there a way to make this happen?

Not with Avidemux. Prepare audio used as track 1 e.g. with Audacity, then use the resulting file as external audio track in Avidemux.

If the audio track is longer than the video, is there a way to save the file so that the audio plays to its end point?

Not with Avidemux, Avidemux will always use the duration of the video track as maximum duration of the video.

The Wiki is outdated, to achieve the goal with Avidemux, first use the "Still Image" video filter to extend the video track by replicating the last picture for the required period of time, save the video, then load the result in Avidemux and add the audio as an external audio track.

[BG Davis]

Thanks!