I've already bought a slightly newer used device, but I'm still very attached to my old one. Unfortunately, I don't know how you can fix the problems with the mouse and touchpad. Are you on Wayland or Xorg? If you're on Wayland you could try to switch to Xorg. Have you tried Zorin lite?
I'm wondering if the suggestion given here may help you:
Since I don't always have problems with the fan, I rule out a clogged fan. In the Bodhi live session, for example, I can watch videos perfectly and the fan runs normally.