HMC-155 and Macbook Air

Hi Noah,
Last summer you answered my question and bought HMC-155. I'm going to shoot documentary with it on location.

Question 1
I am thinking of buying a Macbook air so that I can copy the footage from SD card to portable Hard Disk like La Cie 1TB rugged triple interface and edit on my iMac at home.

What do you say? I am reluctant to get Macbook Pro since it is heavy for a one person crew to travel abroad with camera, tripod, and so forth. I would edit on FCP. Does Macbook Air make sense in this case?

Question 2
After I edit the video on my iMac, can I use Macbook air to show one hour HD video, plugging it to a projector with a VGA adaptor? I am having trouble showing to people what I edited. If I can do it, how can I?

Thank you in advance.

Best, Nanako