So for sub docks, if I go into fullscreen on an app, I still have a little protrusion of the arrow from them. I presume the arrow is supposed to go right, and thus, no obstruction. But it doesn't. Any idea how to fix?

Edit: Make sure you click on the image. Otherwise you won't see the thing I'm talking about.

Well, I clicked on the image, but I still can't see what you are talking about lol

Why the tight crop? I can't even understand to which screen edge the dock is docked to... the arrow is supposed to go right?!

Notice how the arrow is still up even when the dock is unopened. And the crop cannot be any looser, as it is docked in the bottom.

Look, you're giving me a such a tiny picture that it doesn't even allow me to determine/understand what the problem actually is or even what icon size you are using for your dock. A screenshot of your whole desktop would be much better.

Sub-dock indicators are always visible, they indicate that that particular item is a sub-dock. If your icon size is too low (e.g. 16x16 icons or something smaller like that) then the sub-dock indicators will take a substantial part of each dock tile as can be seen in the tiny, tiny, picture you provided.