Forsooth! Ye old program: TwoWorlds.exe has stopped working...Windows dost now seeketh a solution...
In order ot get this game to run, I had to uninstall nvidia physx, install the aigea version included with the game, re-install current version ontop.
Windows 7 64 Pro

Also playing on 7 64bits but installed last physx drivers and reinstalled direcX 9.0c.
Had some crashes at the begining but now it runs for hours without problems.

Actually, games using DX9 or earlier still use DX9 files even if you have DX10+ available. Microsoft split things up like this so that they could significantly overhaul and extend DirectX for DX10+ without worrying about breaking backwards compatibility.
For this reason you should still install DX9 files when a game bundles with them; many will run just fine with what you have already, but giving the game the exact versions it was made with ensures maximum compatibility.

I'm still very early to the game but I noticed that some NPCs when they are talking their lips or mouths don't move, is this a common bug?

Seems so, happens with my game too. ;)