It really is an either/or deal.
Why should I choose either or? The whole point of this is to make a machine that has multiple capabilities with power consumption options. Yeah, the laptop is heavy and dead weight when I am using the ARM or SoC, but it is there for when I do need to perform those more processor intensive tasks.
An adversary could compromise your box with either a vulnerability in an ARM distro, or an x86 one.
This is a valid point. Maybe my fantasy of a server/workstation opens up more vulnerabilities, but this hardware is capable of having better security if I NEVER connect the LAPTOP to a network and I only use the ARM/SoC for network connected activities such as browsing or sharing footage (p2p).
I can reinstall my ARM/SoC image every time I plug in and turn the actual laptop. I can run a check sum of the ARM/SoC image with the laptop before I even install it. The laptop is normally off, so attackers would have to gain physical access of the device. Maybe I was wrong about running a checksum on the laptop image with the ARM/SoC because it would take too long. So, it would be better to have multi-boot options on the laptop.
There is a method to my madness. Have you seen Kodi firesticks? Kodi, formally XBMC, is a media center that runs on linux/GNU and other embedded devices. Some people flash the Amazon firestick with Kodi installations with Add-ons pre-installed. There are dozens of legitimate Add-ons that offer amazing content such as RedBullTV, Crackle, Young Turks Network, ETC. These add-ons are basically only links to youtube channels, but if you can offer your own content alongside the content of other content you and your intended audience might enjoy then all you gotta do is flip them a firestick and they plug it into their TV.
Ahh, and as for crypto-currency mining. There are AMD chips with onboard GPU, but I do not know about making a distro with crypto-currency mining capabilities installed per the GPL. It appears to be a gray area in my mind, but there might be good purpose for this type of operation, but that goes against the security protocol of never connecting the laptop to a network.
I was trying to work towards something along the lines of "Plug in laptop. Laptop serves up footage to p2p network. Laptop mines coin. Coin is insurance against the deck." But violating the GPL is wrong.
I was learning NAS and everything so I could jail plex servers and torrent servers.