Hi Ned,
My name is Keith Robinson I am an account representative over here at Fliqz.
If you upload a 16:9 video to Fliqz, we will automatically letterbox the video to preserve the aspect ratio. If you want to avoid letterboxing, you will get best results shooting your original video in 4:3. Cropping may result in some distortion.
As far as framerate goes, we suggest a constant frame rate of 30 fps, and a keyframe rate to match (every 30 frames/1 per second).
If you would like to have a more detailed conversation about export settings or anything else, I am available to help via email or phone.
Thanks,
Keith Robinson
krobinson@fliqz.com
510-652-3500 X128