My setup is a split 40% keyboard with a columnar staggered layout (corne), I've got layers for a numpad and mouse emulation keys, and my window manager is i3 and firefox has the tridactyl extension. I very very rarely have to touch a mouse, for the odd times I use it the mouse emulation in QMK is usually enough. I find this is the most comfortable typing experience for me.
But yeah, basically don't discount the benefits of 40% boards because you tried an ortholinear board, I found them uncomfortable too.
All pro gamers use a somewhat low sensitivity which forces the movement to come from the forearm instead of the wrist. Higher accuracy isn't the only reason, you'll get chronic wrist pain within a couple of months if the mouse movement comes from your wrist.
I'd recommend at least 20cm/360, better 25+. No accel.
Or you could just move the mouse with your fingers. Other positives include requiring much less space and not looking silly flailing around. (My preference is maybe 1–2 cm corner-to-corner, with no wrist related issues a couple decades in; and obviously, mouse acceleration is a great idea.)