Exporting 5S "Slow Motion" Video for post processing.

I'm looking for a generic solution to changing the frame rate on "slow motion" (120fps) video down to 30fps. I'm a novice at this so it's a bit of a struggle.

Currently I'm using ffmpeg presentation time stamp (pts) plus framerate (-r). e.g.

ffmpeg -i my.MOV -filter "setpts=4.0*PTS" -qscale 1 -r 30 my.mp4

Real or potential problems:

1) I've only worked with files pulled with Image Capture. This ignores the slo-mo region from the iPhone.

2) All the audio is in the first quarter of the clip (well that's not too surprising).

3) -qscale 1 may be too high but of course what I really want to do is copy through.

4) Since I'm not copying the frames through it takes encoding time.

I'd prefer not to buy a pricey tool just to effectively change the FPS but using ffmpeg is a bit clunky (the way I'm using it).

Does anyone have thoughts on a better solution that uses only original frames (no synthetic frames please), allows both normal and slow motion and produces output that readily imports into iMovie?