Don't raise on click: if you can remember to cmd-click, this mostly works, even with right-clicking. The window receives the click and doesn't raise.
Point to focus: you can get this with yabai [0]; note that it recommends disabling SIP (and keeping it disabled) so that it can install some hooks into Dock.app, but you don't need to do that if you only want focus-follows-mouse.
select/single-click paste: you can get pretty far with hammerspoon (hs.eventtap to notice mouse drags, double-, and triple-clicks, and then use hs.uielement to get the text that is selected), but it's handicapped by apps that don't play nicely with accessibility (browsers and electron apps in particular come to mind). [1] has an alternate way which notices selections as above and then uses hs.eventtap to send synthetic cmd-c keydown/keyup events, but I haven't tried it.
edit: now that I think about it, I think you might be able to do the don't-raise-on-click behavior with hammerspoon as well, by capturing click events, checking their `mouseEventWindowUnderMousePointer` property (see [2]), and if that is not the window that is currently focused, block that event and send a synthetic copy with cmd- added (and if cmd- is already in the mod mask, treat it as "I want to raise that window" and do the opposite -- block the event, copy it and remove the cmd- modifier, and post that synthetic event)
[0] https://github.com/koekeishiya/yabai [1] https://github.com/Hammerspoon/hammerspoon/issues/2196#issue... [2] https://www.hammerspoon.org/docs/hs.eventtap.event.html#prop...
