Steam does not force patches, but have them only on auto-update by default. By right-clicking the game in the library you can open a menu. Select "Properties" and on pop-up window choose updates-tab and disable auto-updates for that single game. Not updating the games may lead into version mismatches and perhaps even to refusal to launch the game successfully.
Not all the game developers manage to fix bugs via patches, but create more. Should you have any doubts, disable auto-patching and browse for news and forums. If people complain about new problems don't update until there are hot fixes. If everyone cheers the new patch I guess there should be no problems to proceed with patching.
