Can I set up guest boxes with embedded vm? I want to use AA to route calls to tech boxes that techs don not have phones and then have vm notify tech of message.

Surely you can. Just make users out of the extension range. When you make a new user, it will ask you if you want to make an extension (h.323 or SIP) just say no, and do not worry about the caution error saying that the extension doesnt exist. Just a fault of Manager.

I am missing something in my setup. I set up an incoming call route to go to AA. The call rings 1 1/2 times on all phones and then is picked up. I hear no greeting and then it rings the fall back phone. I have recorded all the greetings. Where do I tell it to answer immediately? Is there some time setup I am missing?

One issue with Embedded is that you don't have Message Notification to a cell phone or pager.

You must create a user without an extension. Then go to Forwarding and check Forward Unconditional, To Voicemail, and Forward Internal Calls. This will cause the VM to answer immediately.

What are you trying to accomplish?
If you want your AA to answer immediately, direct your incoming call route to the AA by using the destination:
AA:Main (assuming your AA is named "Main"

As for the recording, the default attendant is number 1, so the code would be *8401, *8402 for the second AA, etc.