I'm kind of surprised that Linux wouldn't work well on it - the EVOO has better specs than an early 2000s PC, not to mention Unix workstations from the 1990s that people did all kinds of engineering, scientific, and programming work on.
> ultra-modern kernel, and lightweight Wayland display manager
That might not be good. How about a stripped-down kernel (Linux or BSD) and old-school X11 with twm (flwm if you must.)
> The laptop frequently took as long as 12 seconds just to launch Firefox
Ah well, that's the problem isn't it - the modern web and all of its baggage. I think we need something lighter than Firefox that still works OK with Youtube. Maybe NetSurf?