Live Streaming to OSX

You need to get a HDMI capture card, like the ones here from BlackMagic in order to use thunderbolt port as HDMI input.

http://www.blackmagicdesign.com/products/intensity

Let me know if you come across anything other than IR remote controls, and LANC controller cables.

Non retina MacBookPros have Firewire 800 port, and the Canon Vixia HV20,30,40 can be hooked up for livestreaming just by using a firewire cable.

 

ctyhntr really addressed this nicely, so I echo everything said there and am just trying to fill in a few gaps.

You're really asking about two separate functions -- control and recording. I'm not familiar with the Legria series so I won't be able to address the control part in too much detail, but with the LANC port you should be able to do most of the controls you asked about. Not sure about exposure, but the rest should be easy. As for recording, I'm not clearly understanding why you want to record on your MBP -- why not just record directly to the memory card and import it once you land? I'm not aware of any MBP that has HDMI input capabilities, the only option I've ever seen is for output as a second display. And while I don't specifically have the Intensity, I've used plenty of BlackMagic gear and that would have been my suggestion as well.