Your sure about steam? I mean sure you can't choose to stay on certain patches..but you can on or off.
Nope, if you launch the game it will force you to download the latest patch, or you cannot play it. In addition, if Steam becomes aware of a patch, I think if you go offline after that point, you can't play the game offline since it will tell you that it needs updated. IN ADDITION, I'm almost certain that I used to try to set this setting with Steam Mirror's Edge, since I was modding it, and the setting would sometimes randomly enable itself again(potentially if you launch the game).
you can, just choose do not update this game by right clicking it
Nope, if you launch the game you have to download the latest patch.
I'm pretty sure it'll force you to update before you can launch the game even if updates are disabled.
Bingo.
Nope. Not as far as I know.
I have been complaining about this exact issue for probably years, and I have never ever seen any proof that it is possible to launch a Steam game, with the "disable updates" option set in Steam, when there is a new update available, without Steam first forcing you to update the game. I think Skyrim was a relatively recent example of a major game with this issue. Originally, the Skyrim executable didn't even require Steam to be running, which was awesome! But then they patched in the Steamworks DRM, and they kept releasing patches that would overwrite people's modded .exe patches unless they ran in offline mode, or recopied old .exe versions to overwrite the Steam version.
If ANYONE has proof that you can launch an out of date game on Steam now, with updates disabled, without Steam forcing you to update, I would welcome that and gladly admit I'm wrong, but as far as I know the option is still useless aside from saving you download bandwidth for games you have installed but don't play.