Recording Hi8 SD NTSC home movies ideal quality with ffmpeg?
I would suggest encoding to H264 in MP4. Making it square-pixel is fine, Deinterlace first. Doubling framerate has no use here (Exception would be if you used an interpolation filter to generate full frames for each existing field, but that's not needed here).  

ffmpeg -f alsa -thread_queue_size 1024 -t 1500 -i hw:2
       -f video4linux2 -video_size 720x480 -framerate 30000/1001 -i /dev/video0
       -vf yadif,scale=640:480,setsar=1
       -c:v libx264 -crf 21 movie_0001.mp4