It is scored as a single, out at second.
No, this is an appeal call only. This is not the umpires call unless asked on appeal.
YES he can be called out on an appeal... this would be the same as if a home was hit and the runner had not tagged first base ...
A double is when the batter reaches second base on a hit ball.
Yes, the batter made it safely to second base. Therefore, he is credited with a double.
a stand up double in baseball is when the batter hits a double and doesn't have to slide at second.
On a ground rule double, the batter is awarded second base and all runners advance two bases. The ball is dead.