Accelerating expansion of the Universe

I am asking here because I feel like the questions are more narrow/specific to physics than to general /r/science (plus, I'm assuming a lot of physicists hang out here, so it's more likely to get a more informed explanation. I studied physics in college only up to E&M, and have just basic knowledge of relativity and quantum mechanics. So apology if this question is too "dumb"/elementary. :)

I heard again and again (example) that the Universe is expanding and that its expansion is accelerating. I understand the basic concept of how we detect the expansion (redshift in the wavelength of lights/radio waves arriving at our observatories/satellites?). But what I don't understand are:

1. Is the universe accelerating in every direction that we can possibly detect? That is, for every stars/objects we see in the sky, we detect that they are accelerating away from each other (the gap among them is getting bigger)? Or is it accelerating on average (some objects seem to be coming closer to each other, but on average scheme of things, they are still separating apart from one another)?

2. Could it be possible that the effect of the gravitational forces among celestial objects haven't gotten to the point where they override the original acceleration caused by the big bang (or whichever phenomenon that started the expansion)? In other words, could it be possible that we are observing the universe in the time when it is still expanding from the big bang? How do we confidently know that the universe has been and will always be expanding with increasing acceleration (and therefore, the need to account for dark energy, etc.) and that we are not just in a "phase" where thing are simply accelerating (and will come to a halt or even contraction)?

Again, please keep in mind that I am a layman trying to understand a bit more about the expansion of the universe and the dark energy. So do not take this post/question as an attack toward existing theories. I just want to understand better (or be redirected to informative resources that explain it for layman). Thanks so much for your answers that might educate me more about the physics!

Submitted January 27, 2016 at 04:47PM by plartoo http://ift.tt/1PU7NGl