Well, that's part of the problem.
It started happening after the aug. 3rd updated.
I've installed and re-installed almost every kernel available in mhwd, there no errors during installation, no error during grub update and no error when it boots to black screen.
3 of the 5 journals I posted at your request are the failed boots.
[Hour later EDIT]: So I've installed and tinkered with multiple kernels. Always get a black screen on reboot with each and have to use grub advanced menu to reselect the same kernel for it to boot. And zero errors. I'm obviously looking in the wrong place or something.
So I decided to grab another mouse (was using a razer) and remove openrazer dkms.
But I kept thinking about no error message and decided to take out quiet from grub so I could perhaps see where it was hanging or something, anything.
I've rebooted with Linux52 12 times so far with quiet removed and it hasn't hung once.
Is Manjaro messing with me?