It happens, but not very often.
No, in Major League Baseball a base runner can slide into any base in any direction.
Yes . But why?
If they are holding on to their gloves they cannot dive palms down and road rash them, also outstretched fingers often get jammed on the base or cleated by the short stop. In the event they have to slide into the base, they stand the chance of ruining the gloves given they slide into the base using their hands. They slide head first and the gloves are expensive. I heard that some also do that to remind them not to slide head-first.
Yes.
Yes, a runner may slide into any base at any time.
Before 1900
You can slide into 1st base. Generally, it is not recommended. There are two scenarios where you may want to slide into first. 1) You have hit the ball and are running toward first. The first baseman is positioning to receive the throw. You can see that the throw is offline and the defender may try to tag you instead of touching the base, or the throw has put the defender in your basepath. You slide to avoid a tag or the defender. 2) You have a base hit and have rounded the bag. A throw is coming toward 1st base and you need to return. You may want to slide back to the bag to avoid the tag while off the base.
No. And it really does not improve your speed to the base.
yes
Yes you can slide into first base. It has been done in Major contention games where every out counted. I.E. game 5 or 6 or 7 of a world series, division series, or the like. 9th inning. It is not comonly see because it is usually your close or you out when you hit the ball.
"Will the player try to steal first base in the next inning?"
if the player strikes out and the catcher drops the ball, the player tries to beat the catcher's throw to first base. If he reaches first before being tagged or thrown out at first, he is awarded first base.