FFMPEG convert video with multiple audio streams?
If you copied your command there then your issue is probably -acodec:0 mp. That should be -acodec:0 mp3.

You can just use -c:a mp3 to apply the encoding options to all audio tracks at once, no need to apply them for each individually.

Other than that your mapping is correct and shouldn't be the issue.

Edit: To conclude the discussion in the comments regarding the actual reason behind the question: When it comes to editing it is no problem to just transcode the video stream if the source codec makes problems and import the audio from the source file by either muxing the audio into a new container with the transcoded video stream or just importing the transcoded video and audio streams separately (by demuxing the source) into your editing program and skip on the container format.