Maan I've missed posting a bunch of things for my future self.
Here are a couple.
When using geda's pcb layout, if you set the pad clearance on parts to zero, you can do honest copper pours for ultra-high-power or heat-dissipation situations. Tricky because the copper won't separate from unintended pads, so you need to know what you're doing when you pour the copper. Best done by running all the traces, then running the copper over them, then deleting them, so you know you're not inadvertently shorting.

Gnome3 has very irritating sliders on all the windows. A suggestion for disabling these:
# echo export LIBOVERLAY_SCROLLBAR=0 > /etc/X11/Xsession.d/80overlayscrollbars