How do the Warding Bond and Sanctuary spells interact?

So I (war cleric) and my friend (paladin) want to use warding bond. It says:

[…] While the target is within 60 feet of you, it gains a +1 bonus to AC and saving throws, and it has resistance to all damage. Also, each time it takes damage, you take the same amount of damage. […]

So the questions are:

  1. If I cast sanctuary on myself, does the enemy who attack my friend have to roll a saving throw first before it hits me because of warding bond? Or does warding bond nullify the sanctuary effect on me?
  2. Is it okay to cast healing spells inside the sanctuary?
  3. If I have the defensive duelist feat, can I use my reaction to nullify the attack I got from warding bond?