The main focus of the thread has been shifted towered softwares rather than laptops. So, for video editing you will need a powerful computer. A desktop, iMac or Macpro would be ideal in this case. But if portability is a must, then buy a macbook pro rather than a laptop. For software wise, if you do professional paid work, then choose final cut pro x or Adobe Premier Pro. If you do this for fun and not getting paid, use a free program like iMovie or Pirate something like Vegas pro, because they are easy to use.
As for Blender vs Premier Pro vs After Effects, they are 3 different things. Adobe Premier Pro is a dedicated commercial used video editor. After Effects is a compositor which used to create visual effects. Blender is an application that has compositor and NLE built in. But it is designed for 3d modeling, animating, and rendering 3d scenes. It is a powerful open source 3d software. Sure Blender can do what After Effects does. But it require lot of experience and time as you have to build the effects from scratch. That's where after effects plugins come in. Because, the less time you have to spend a project, the better. And the Blender's video editor interface is not that user friendly in my honest opinion.
Finally, it all comes down to the personal preference. Some people prefer Blender, because it's like 3 birds with one stone (Premier/After Effects, Cinema 4d). For me, I prefer Final Cut + After Effects because I'm used to it and it suits my need. So ultimately, you should choose what's best for you. Others can't choose it for you.
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