The statement about the ball being driven further with a heavier bat, assuming it is swung at the same speed ("everything else being equal") is true, although it probably is not true that everything else is equal. And the statement about being driven farther with a faster bat is also certainly true.
The statement about the weight of Ruth's body limiting (in my language) the recoil of the bat is not exactly true. Inspection of high-speed video from MLB games reveals that the bat slows down condsiderably after impact, a consequence of Newton's "action-reaction" law. That is, the bat exerts a force on the ball toward the pitcher, so the ball must exert an equal and opposite force on the bat toward the catcher. Although the bat does not recoil backward because it is already moving forward, it does slow down. And there is nothing the batter can do to influence that.