Possible to shorten jacket length from the shoulder?

This is impossible unless you are talking about deconstructing and reconstructing the whole jacket.
Even then it still might be impossible or extremely difficult and prohibitively expensive.

No decent tailor would even think of doing this. If nothing else then consider the arm hole and how it will look if the sleeve started half way down.

A really killed tailor (who has balls of steel) might be able to shorten the jacket, but move the pocket flaps up a little so that their original position is still covered by the flap, but you're going far too far in the name of balance. 2" off of a coat will not make it look terrible, and after a few weeks you will have forgotten how it looked originally.

I think you misunderstood the question. OP is not talking about shortening the length of the jacket, but shortening the sleeve length by shortening the sleeves at the shoulder seam. Not shortening at the sleeve end. Yes, tailors do this. It costs more...I've been quoted $75-100. JT

See i would agree with you if he just said "button holes" but he said "buttons/pockets" and there are no pockets on the sleeve

 

Pardon but I think you are the one who misunderstood the OP. See bold where OP refers to both buttonholes and pockets. As far as I've seen I've never come across suit sleeves with pockets on them. Although on this forum I wouldn't be surprised.

 

My bad...I just saw button holes on first read and thought he was talking about working sleeve buttons. Thanks for the heads up. JT

You are basically asking if a premade jacket can be taken apart and completely reconstructed to fit you.

The answer is yes, provided there is enough material. Forum member who is a tailor has done so by taking apart a TomFord suit.

But realistically, don't ever buy "GREAT DEAL" anything that don't fit up front. Because it well cost you an arm and a leg to make it fit, if that is even possible

To do this you would have to take the sleeves completely off and the collar completely off. Also, there would need to be room in the armholes to allow for it. This can be done, but I would think it would be expensive if you could find somebody willing to do it. Also your buttoning point will change and can throw off the proportions. I would say get the hem taken up 1" and live with it that way.