Hi ShootingStars
I would investigate GoPro/Cineform as your intermediate 'codec'. You can edit [virtually] visually lossless files on your laptop without using much processor power. The codec itself is professionally highly regarded – but their software can be a bit flaky. :/
I'd recommend encoding MLraw (or even H264 will benefit) > Cineform. Then you can edit these files easily in something like Premiere (on Windows). If you choose a high enough quality of Cineform encode you can avoid round-tripping; Grade in your favourite application, and then edit out an 'online' edit straight out of the Cineform files to your chosen finished export flavour.
It can be a bit of a confusing workflow to start with, but I'd say it's well worth the time and effort learning it if you have limited hardware power.
Have a look here for a start:
http://cineform.com/technologytimbytheriver