Can you hoard cubes in your protected zone?
What rule would prevent you?
None. So, yes. You can hoard cubes. The largest problem would be that you’d probably block off your pathway to the corner goal. And your opponents can steal from your protected zone. (As a robot, you are protected there, however.)
Outer protected, yes. Inner protected, no, as even crossing any part of your robot into your opponent’s inner protected zone is an automatic DQ (unless forced there by an opponent).
Yes, outer protected. Because hoarding in the inner protected (scoring) zone would be pointless, and would just count as “scored.” (And that’s the terminology I’d expect to be used to refer to the “inner protected zone”)
The inner protected zone is not the same thing as the protected goal zone. The inner protected zone is the entire 2’x2’ tile that the protected goal zone is a part of.
You are able to. However this is not a smart choice due to the fact that there are many on the field.