Your definitions go from subjective to wrong depending on which concept you're proffering in which paragraph. You need to research more thoroughly before you make sweeping statements. There are several nuances of "atheist" and... an "anti-theist" is against religion or more specifically, organized religion, not a god denier. You can be a believer and still be anti-theist.

I am an atheist who is also an anti-theist. I also object to having to "be" something because I'm "not" something. You don't see people who don't collect stamps as "anti-stamp collectors" or people who don't ski as "anti-skiers". No belief is the default position, I should not have to make a claim to be anti anything.

My son is junior @UMBC... where did you find that study?

Let's not mess with what either of us says he is.

You could also use the concept of "theological noncognitivism" as the classical definition of agnosticism, and the "postive atheism" as the classical definition of atheism.

But both are pragmatic atheists, and both can be anti-theists (religions must be destroyed) or closer to apatheists (not my fucking job to care for this shit).

The 3 ways of treating the claim are nicely explained.
But the name you give to them are (at least in relation to the classical definitions) incorrect.
The atheist approach is exactly believing there is no rescue and acting as if there is no rescue.
The agnostic es the second explained. "It is useless to discuss if rescue is or not coming, so we act with what we know and try to escape or at least plan to endure as long as possible.

Again, it is just a problem of how you call the 2 last approaches not the idea.

Also someone that accept the agnostic "argument" probably won't choose to act as if there is a specific god, so when you say agnostic, the "agnostic acting as the world is atheist until some evidence arises" is not necessary, you can for simplicity use only one word.

And then the Atheist is a summary also of "I believe that the lack of evidence for a divinity demonstrates that there is no god so I can claim that the world is atheist".

As agnostic I see that agnostics more than claiming to not know, they claim that by all presented propositions of god, the concept is meaningless, as the garage dragon. The existence or not will lead to the same results as there is no detectable "action" of those gods that are not explained by nature or something like "random uncontrolled variables". So the classical agnostic won't even bother discussing or creating reasons for existence or not.

Anti-theist is more a political stance to active put yourself against religion than a matter of believing or not.

But again, is just a matter of naming, if you want to name the concepts as Schruble, ni-hong and wakawaka, does not matter, as long as we can communicate.