If your alternative is AMD then this has been discussed quite a few times before.
https://forums.puri.sm/t/should-the-next-librem-be-amd-based/3010
If your alternative is RISC-V, follow the links at
https://forums.puri.sm/t/riscv-and-sifive-and-stuff/9170
(anyway, not at the required level of performance at the current time, not even close)
If your alternative is POWER,
Maybe you had a more creative alternative in mind that has not already been discussed. 
(and which you would like to share with us)
My summary answers:
- every choice is a compromise in practice
- Intel is the least bad option at the moment
- the CPU itself is only one aspect - you also need a chipset ecosystem that is as open as possible
- better the devil you know …
Verify the .iso before you even burn it onto a CD / write it onto a USB flash drive. No matter where you download from (could be shady as), verify the hash of the downloaded file against the hash value provided by the official web site.
There is no point verifying the hash of a torrent-downloaded file against a hash value that is itself torrent-downloaded. (Yes, technically, the official web site may provide signed hash values which it would then be safe to torrent-download.) Anyway, there is no reason not to get the hash value from the official web site, whether signed or not.