What think?  

That's already the case but you might have it disabled, check option or it's also a hotkey still "Atl+C". Thanks to @guerringuerrin this hotkey will be unassigned next release as it tends to troll people. Also in the PR i made all range overlay are forced enabled for the placement previews.

Is there a way to also show ranges of buildings that shoot arrows? To know where to place buildings. Ideally showing all these ranges when pressing something, while not cancelling the placement process.

thanks, ill see if i can figure this out, but its probably above my paygrade

Works for all buildings  Will do for the PR. Sure, I've just added to ModernGUI so you can pull if you want. If you want to add it to CWA because it helps understand some of your buildings mechanics you can just copy past this file : https://gitlab.com/4trik/ModernGUI/-/blob/master/simulation/components/GuiInterface~auraInBuildingPlacement.js  Conveniently holding in a single isolated mod file for you to do so, but of course, unrelated to your request