Have you considered at least testing Helium Frog? That works on Mac right?
Doesn't matter if you hate it, just use it to test the image quality.
I'm confused a bit by the black bars, as they shouldn't be there in a true 1080p image. Were they put in after the image was shot, or were you filming in some odd wide-screen/full-screen setting? (For example, you shot the frames in full-screen, but told it to export in wide-screen.)
I'm sadly not to knowledgeable with those two pieces of software, but have you compared these pictures to ones you've just snapped with the Logitech Webcam software? Snap a few at the same res and see if there is any difference. If not, it may be your camera, if so, then that will confirm your suspicion about the software.
Now, I save in an uncompressed .Avi format, is there something similar in the export settings on those programs?
The compression right off of the bat may be part of the problem, as the video has been compressed and changed several times on it's way to Youtube.
Comparing your shot to one of my pictures, I'm not seeing any major quality difference. Yes, the depth of field on the 910 is locked, and not the greatest at close range, but the figure looks just fine to me. Perhaps a bit of difference, but nothing that couldn't be attributed to a totally different set-up, lighting and shot.
If we're talking about just the in-focus figure, the only reason things don't look quite as good are the lower quality printing, and lighting/set-up. Also, not every camera will be identical in every way. If we're talking about the rest of the image, it's simply depth-of-field. They're just not in focus, that's all.
And if I'm totally missing something here, just tell me. It's really, really late here. 
As for wide-screen, just check all around in the capture settings menu. And if you have to film in something full screen, if the pixel count is high enough, you can just crop off the top and bottom and make it wide-screen 1080p. I'll be downloading SAM tomorrow, (Or would that me later today?) and will be able to help more then.