If the device is going to be successful though, it will need to attract people who can barely use the preinstalled Windows on a device bought from a store shelf.
The Pandora was a niche device and I see no reason to assume that the Pyra will be any different. Sure, there will be Windows users without any knowledge about Linux, but I don't see them making up a significant number of the total users.
Answers to navigation and application install questions need to be point and click paths, not command line strings.
I disagree.
I find the very idea of making a system "beginner friendly" (whatever that means) a flawed concept. There is nothing wrong with being a beginner, but the beginner should have the ambition to become sufficently advanced. There is nothing wrong with taking him by the hand but he should walk on his own feet. This means, the system shouldn't be dumbed-down. Instead the beginner should learn how to use it properly. And properly using a unixoid system means to get familiar with shells.
After all, people are born illiterate, but we don't design our society to work without text - we teach children how to read. Nobody starts as a good car driver, but instead of making our streets look like bumper car courts we have people go through driving schools.
What I didn't mention when I said I jumped in at the deep end with Debian on my 2nd attempt was, that my 1st attempt was with Suse, which was very popular in Germany back then. Superficially it was pretty close to Windows, but what seemed to be helpful at the beginning turned out to handicap my progress in understanding Linux. After a while I found myself constantly mixing up how things work under Windows and Linux, which was cumbersome on both systems.
With Debian it was a whole different story. It made me understand right from the beginning that I know nothing about it and that I'll have to learn quite some things from scratch if I want to work with this system. What followed was said 6 months of headaches, but when I started to see the whole picture it all felt very natural.
The point is, that beginners should embrace the new system the way it is meant to be, instead of trying to bend it until it looks like their old one.
I consider switching to Debian at some point.
Where's the difference to Mint (since it's also Debian based)?
For me personally, an important feature of Debian is its social contract. [1]
On the technical side, Debian's main advantages over Mint are its sane and stable package base, and its close following of security issues.
The only actual advantage I see in Mint is, that they really put some effort into GUI design.
Other than that there is really no big difference. Debian-based distributions all pretty much work the same, no matter if it's Debian, Ubuntu or some other derivative. If you know how one works under the hood, you can handle any of them.
[1]
https://www.debian.org/social_contract