I have my queens hotkeyed so I can double tap the key, hit V for spawn larvae, then click my hatchery. However, I would like to get rid of the need for the mouse click. Can I somehow select the target for my spawn larvae with just a hotkey? That way I could keep my larvae flowing with less distraction.
You can't avoid to click, but you can click on the minimap.
If you select all your queens (say in a single control group) and cast spawn larva on the minimap, the closest queen will cast spawn larva on the closest hatchery to where you clicked.
This is another function of smart casting.
This isn't possible. The way you're doing it is likely the fastest you can hope for.
I do see this is a very old question. But, here is another, even better, method. If you have all your queens on a single hot key. Then to spawn larve on all your hatcheries all you need to do is hold shift, click V once, then hit your button to cycle through all your bases. The default key for this is backspace. However, I switched that key for me to "tab".
Using this method all you need to click is the hotkey, then keep your mouse centered on the screen and click after each tab. You can do this very quickly between a great number of bases. This is way more simple then clicking the hatcheries on the mini-map as this method takes precision to hit such a small target accurately.