The Lenovo X140e is a ThinkPad.[1] I didn't blindly trust Ubuntu's certification. I made sure to get a brand that historically has had good Linux support. I also knew about Nvidia graphics and avoided them. Still, I got burned.
I don't doubt your checklist is good advice for buying a Linux laptop, but it's simply too time consuming to check all of those things. Even if it wasn't, the likelihood of everything working well is low. All it takes is one bad driver for one piece of hardware and the laptop becomes a constant annoyance. Considering the number of hardware devices (Bluetooth, wifi, mic, camera(s), trackpad, GPU, fan, power saving, etc.) it's all but certain something will go wrong. Maybe audio won't automatically switch between headphone and speaker output. Maybe the fan will run at a few discrete speeds instead of gradually ramping up/down. Maybe it will wake from sleep if you open the lid, but not if you hit a key on the keyboard.
I'd rather just pay money and get something that I know will work. That's why my main development machine is a MacBook. I wish there was a competing brand of unix laptops, but so far… no dice. :(
1. http://shop.lenovo.com/us/en/laptops/thinkpad/x-series/x140e... Though after I purchased it, some people told me it wasn't a true ThinkPad, whatever that means.