#1 - Generally on a dropped 3rd strike where a bater is safe at first is due to either a wild pitch or passed ball. Usually a passed ball ( the assumption I am making is that the pitch should have bee caught by the catcher).
#2 - I assume you're asking because generally someone hits into a double play which make it easy to score. In some instances (like a strike 'em out/throw 'em out) a double play is credited to the defense but not necessarily an offensive player. This the case here. credit the defense with a double play but each runner is a stand alone out as far as their stats are concerned. (In other words - no hit into double play exists. Just a double play against the offense and credit for the defense.