How do Volatile Arrows work in the vigilante class?

In pathfinder, the vigilante class has a viglante talent Volatile Arrows:

Volatile Arrows (Ex): A vigilante with this talent gains the ability to attach an alchemist bomb to a ranged attack he makes with a bow or crossbow as part of firing the attack. If the attack hits, it deals an additional amount of damage equal to that of an alchemist bomb, using the vigilante’s level as his alchemist level to determine the bomb’s damage. He can use this ability a number of times per day equal to 3 + his Intelligence modifier. The vigilante can takes this talent multiple times. Each time he does, he can use the ability one additional time per day and he gains one alchemist discovery that can modify bombs, treating his vigilante level as his alchemist level for any prerequisites. He can apply these discoveries to his bombs as normal.

What’s not clear to me is how exactly this works, and what properties of bombs from the alchemist class are carried over into the attack. More precisely,

  1. Do the bombs still use touch AC (with the arrows acting separately)?
  2. If the bombs arrows miss, do the bombs still detonate?
  3. Do the bombs deal splash damage?
  4. Can the vigilante do this multiple times per round (making the Fast Bombs discovery nearly pointless)?
  5. What discoveries count as modifying bombs? (E.g. sticky bomb? rocket bomb? etc.)
  6. What about Healing Bombs? Does the arrow do damage and then the bomb heal?

My guess is that the bombs merely do extra damage on the direct hit (determined by whether the arrow hits), and nothing else is taken into consideration beyond discoveries. This would mean the answers would be (1) no, (2) no, (3) no, (4) yes, (6) yes. (5) is a little tricky, but I expect the most reasonable answer to be "anything with a ‘*’ next to its name" (a bomb can only be modified by one discovery with a ‘*’ at a time).