Beyond Time and Space?

What exists outside of space and time? I started pondering this idea recently, having talked with a theist about it not long ago. Now, I know that there's no definitive answer to this question from a scientific standpoint. Some scientists believe that nothing exists beyond our universe, whether it's infinite or just unimaginably vast; others believe that other universes are beyond ours in a multiverse, containing possibly an infinite number of these other universes, which also may or may not be infinite in size and may or may not be similar to our own. These are the predominant theories according to the most brilliant minds that humanity has to offer, and I accept that we as a species may never know the actual answer to this particular debate, but these are both plausible compared to the third alternative that I have stumbled across. Theists have provided this third alternative, which states that God is beyond time and space.

So, in the thinking about this third alternative, I have to reject it. The idea that a single entity that is infinite and timeless could not be feasible if it exists outside the universe it is credited with interacting within. If God is outside the universe, how could it possibly be everywhere within the universe? If God is outside time, how could it be every when in our universe? Logically, it couldn't exist outside space/time and be omnipresent within the boundaries of it, right? I believe so.

Nothing that we have observed within our universe has come from without, so far as I know. I'll admit that I'm not a cosmologist or astronomer, so I haven't made very many observations into the deepest regions of space. However, according to every study I've read and every scientist I've heard speak via video, this is true. There are only objects from our universe in our universe, from the moment time started until now and likely on into the future.

So where does that leave God? Nowhere in the observable universe, not in any spectrum of detectable energy from radio waves to gamma waves. Considering we also see the universe as it was relative to it's distance away from us, God is also not in any period of time that we can observe. I posit then that there is no God in this universe, at the very least, especially not one that is described by most theists. 

I know that these points are not new by any means, and I'm sure that you have probably heard/read this a plethora of times before. I just felt that I needed to share my take on the subject. Now I want to leave you with a couple of questions, because I want to see what you all have to say. 

First, what do God and nothing share in common?
Second, what do you think exists beyond the time and space that we exist in?
Finally, what is nothing capable of that God is not?