Why not? It has happened plenty of times before, again it is dependent on which stat service is reporting the box score.
Theoretically you could come in with 1 out in the first inning and finish the game and get a save. Assuming the starter never records an out, a RP comes in and gets 1 out, and then the next reliever finishes the game. The scorekeeper could give the win to the RP who got 1 out and the save to the RP who got 26 outs. You could apply the same thing to a hold, just have another reliever get the final out and you have a 1 out win, a 1 out save, and a 25 out hold.
Obviously the scorekeeper since the scorekeeper is supposed to give the win to the most effective pitcher they would give it to the 25/26 out guy. But it isn't set in stone that they have to.
Incorrect again. There needs to be a pitcher of record to record a save - you are not saving anything if there is no winning pitcher. Hence, if a game is not official, there is no save situation.