I would suggest commenting in this thread pretty frequently as there are new questions regarding miscellaneous issues among people who can actually play the game being posted every few minutes. Here are a few other threads with the same problem:
http://answers.ea.com/t5/Battlefield-4/Mouse-and-keyboard-not-working-ingame/m-p/1738363#M22333
http://answers.ea.com/t5/Battlefield-4/Can-t-use-Keyboard-Mouse-in-bf4-PC/m-p/1742357#M23652
3 threads and no proposed solutions.... I pre-ordered this game to get the close beta, couldn't play the closed or open beta due to this same issue, and now I can't play the official release due to the same problem.
One word: unacceptable.
I installed Windows 8.1 from Windows 8 and the problem was solved, I also have cloud disabled on Origin.
