1. Astros went in defensive mode when replacing Altuve to protect lead.
2. In extra innings, you start your at bat with a runner at 2nd base. Whoever made last out in prior inning is put on 2nd base to start their next inning at bat.
3. same as #2. MLB started this a couple of years ago to shorten games. In extras, you start with a runner in scoring position (2nd base) to make it a little easier to score so that games can likely end sooner. No more 12+ inning games. I think since MLB implemented this rule, no games have gone past 13 innings.