Thank you for providing great specs on the equipment you're working with. I too have been computer shopping recently and for video editing Videomaker never recommends editing with less than 4GB of RAM. Even though your footage is plenty small it seems like your laptop is the biggest bottleneck.
Our computers buyer's guide, and there will be an updated one in our September 2013 issue.
And it looks like you'll appreciate this take on refurbished Macs (which is a fine way to go for editing)
But in case you don't want to go with Apple products, I'm considering this one for myself,
Toshiba Satellite S850