To be fair, I can't think of how these features would be terribly useful. I've never encountered a game or program that tells me to press any key except ENTER, or a game that tells me to press ENTER and not touch any other keys. If you can suggest a good use for it to me, then I will submit that it could be useful as a built-in feature.

Avoiding the hardware's three-corners bug.
Also, I edited my post.
EDIT: Edited it even further.

You can "avoid" the three-corners bug already by checking the key you want to check and then making sure the 3 corner keys aren't all pressed as well. For instance:
getKey(47) and not(getKey(48) and getKey(40) and getKey(39))

Although in reality you're not avoiding the bug, you're just changing how it works. Without the fix, pressing the 3 corner keys but not the key you want will result in a false positive. But on the other side of the coin, with the fix, pressing 2 of the corner keys as well as the key you want will result in a false negative.

There are multiple sets of three corners that can set it off, and checking for all of them would be far larger than just checking if only that key is pressed. Also, things get surreal once you start pressing in the top five rows of keys.
In case you're wondering, I made a program for the explicit purpose of investigating this bug

Why must everything be an Axiom?
I also find it interesting that noone's commented on my Window() suggesstion

It's because you're requesting specialized stuff that could be built with Axe's built-in routines.  In other words, you're more-so requesting sub-routines and not actual commands.

His specific command couldn't be written with Axe actually, without some sort of brute forcing of the getKey(A) command.  But we are not saying everything must be an axiom, we are saying things that have very specific uses should be made into Axioms.  Quigibo wanted Axe to have all the general use commands that programmers would use on a regular basis.  He also knew he could never fill all of the requests, and so he created the Axiom system specifically for cases like these, where there is a definite need for a new routine from a programmer, but that routine isn't general enough to be included into the Parser himself. 

Some of these commands are really getting useful.

Did you add ++ and -- for increasing and decreasing like C++?  Those would be nice