Question 1 - Front
Although placing Ad in the back row gives you two pairs instead of one in the back, you will still likely lose to Villain's back row flush. Two pairs does not add any value in terms of royalty points.
Placing Ad in the front row puts you from being "behind" in the front to being "ahead." It also provides a big buffer as Villain will need to pair up or hit another Ace up front to win that row.
Question 2 - Back
Sometimes the most unlikely placement is the most accurate placement. Placing 2s in the back row misses your front pair, straight in the middle and eliminates your back flush potential. But it does one thing right, giving you a non-foul hand AT THE MOMENT.
Since BOTH villains are currently in a fouling position, all you should aim to do here is to make sure your hand holds up.