Why did Capcom cut the Championship off the Super Street Fighter IV Arcade Edition

Option Select refers to combinations of buttons that will result in a different action depending on what the other player is doing. One example is crouching and pressing light kick and light punch, which would perform a throw if you were standing. If the other player tries to throw you while doing this then you will tech the throw but otherwise you will perform a crouching light kick. I don't really know of any other examples or if it is used outside of SF4 but I think it could be.

Hit Confirm is a pretty common fighting game term and relates to combo's where you have time to confirm that you have hit someone with the first attack before continuing with the combo or stopping if it is blocked/misses. This is kind of the opposite to moves which can be cancelled where you will pretty much have to instantaneously perform the next move in the combo for it to work.

Endless mode with the lobby set to just 2 people is the replacement for player matches. Set the other slot to private and you get a friend-only 1v1 mode.