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?"
These are terms from baseball. To 'steal' is to advance one or more bases in a situation where the ball has not been hit: where someone has mishandled the ball, or during a pitch. A 'slide' is what players use when as a base runner they approach a base guarded by a defending player who has or is expected to shortly have the ball. If the defending player touches the runner before he touches the base, the runner is out, so the runner slides, usually foot first, toward the base, in an effort to get past the defender before he can be tagged.