3 Points

A few points on the laws of the 9 days and 9 Av.
1. The Levush 551:14 explains the reason one can't wash clothes is שלא להסיח דעתו מן האבילות but garments of a baby that are constantly soiled, one may wash them שאין בכיבוס זה משום שמחה.  But how does that remove the issue of הסיח דעתו מן האבילות?

2. The Rema 5558 says one can't eat meat the night after 9 Av even if it was Shabbos and pushed to Sunday (when its not the 10th when the Mikdash burnt,) מפני אבילות של יום.  What does that mean, what סברא  is that?

3. From Rabbi Karp - learning דברים הרעים on 9 Av is part of saying kinnot.