Have you looked at Motorola? I'm not sure they have all of those features, but me and you think similarly and when I did research, I ended up choosing their $130 phone for my contractors.
But I main the $900 pixel.
They are so similar its weird, but Motorola was slow with snapchat and the keyboard some time.
Is there an up-to-date list of their phones which allow bootloader unlocking? Not all of them do..