How do Volatile Arrows work in the vigilante class?

Question

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).

Answer 1

1. Do the bombs still use touch AC (with the arrows acting separately)?

• No. The ability doesn't say you do, and you're not attacking with the bomb, so you target AC normally.

2. If the bombs arrows miss, do the bombs still detonate?

• It doesn't appear so. Ask your GM for "common sense" rulings on your attack missing. It likely does not matter because...

3. Do the bombs deal splash damage?

• No. You don't deal the bomb's damage, but add it as "an additional amount of damage" to your existing attack. There is no splash... maybe you used a smaller and/or more directed payload.

4. Can the vigilante do this multiple times per round (making the Fast Bombs discovery nearly pointless)?

• Yes... and kind of. You are not able to make "real" alchemist bombs any faster, but you do seem to be able to use this ability like Fast Bombs because of the phrase "as part of firing the attack."

5. What discoveries count as modifying bombs? (E.g. sticky bomb? rocket bomb? etc.)

• Anything that alters the effects (usually damage type) of the bomb. They can be identified by the asterisks on the Discoveries Archives of Nethys page if you're in doubt ("Discoveries that modify bombs that are marked with an asterisk (*) do not stack.").

6. What about Healing Bombs? Does the arrow do damage and then the bomb heal?

• RAW, the ability causes you to do "an additional amount of damage" so you cannot use it with Healing Bomb. It could be argued that Healing Bomb is more specific and yes, you would do arrow damage and bomb healing at the same time (technically one happens before the other, but it's fairly common that the person whose action it is decides said order). Note that you would still need to expend a potion or infused extract to accomplish this.