Caps look to zoom in and out (doesn't zoom to cursor, unfortunately), and otherwise control groups.

I'd love it if the game had a hotkey to swap targeting behavior (gravity well, local area, hold ground), but alas you need to access this critical function from an obscure sub-menu...

Pretty much yeah; you don't need to be overly quick in this game, and precision counts for a lot more.

Using the Empire Tree well really reduces a lot of the need for hotkey memorization that other RTS games have. Though you may want to go through the list of possible hotkeys and see if any look useful to you, and possibly change them if you prefer a different setup.