A couple of little questions: gnome hunter, Lightning lash

I'm bulding my gnome hunter and ran into a few unclear parts in the rules:

1) Hunter favored class bonus for gnomes. It has some weird phrasing: "Add DR 1/magic to the hunter’s animal companion. Each time the hunter gains another level, the DR increases by ½ (maximum DR 10/magic). ".
What does it actually mean?
a) When you take it on for the first time, it grants DR 1, when you take it again later - +1/2 to DR each time you take it. Seems legit, but the wording is too different from bonuses for other races, that work this way.
b) Once you take it once, it grows as you level up, without investing favored class points in it. Seems strong.
c) Each time you take it, it grants DR 1+1/2 hunter lvl. Seems insanely strong and probably wrong.

2) Lightning lash spell. Looks like fun - my hunter is small, so traditional weapons are not so strong on him. But a few mechanics of the spell are unclear.

Lightning lash

a) Duration. Do I effectively lose 1 round of duration each time, because I cast it as a standart action and can't attack at the same round?
b) Is it considered a whip for the rules? Description says "flashes in your hands like a whip", but the description of "Whip of spiders" states similar moment in a more strict way, for example ("You can wield this object as if it were an actual whip, except you make a melee touch attack with it").
So, is it finessable, or do I add only my Str bonus to it's touch attack? Does it provoke an AoO? Does it have a threat range? Does it work with the whip feats?

1) a. Paizo isn't always consistent with wording across similar abilities.

2) a) Pretty much, unless you have a way to use the lash during the same round you cast it, such as Quicken Spell. (Cf. almost every other spell that grants you a once-per-round ability.)

2) b) No, it just looks like a whip--it is not wielded like one. It's just a special repeatable melee touch attack. You don't take penalties for nonproficiency nor benefit from bonuses like Weapon Focus, and you can affect targets wearing armor without a problem.

2) a) Pretty much, unless you have a way to use the lash during the same round you cast it, such as Quicken Spell. (Cf. almost every other spell that grants you a once-per-round ability.)

Interesting, so, actually, I can use any metamagic to get extra round of use, because it will make casting this a full round action and full-round spells go off at the start of the next round. I think, I'm getting myself a lesser rod of extend spell!

I . . . guess that's one way of looking at it?

A full round cast and a 1 round cast are two different things. Spells that are a full round action still take effect on the round they are cast. Spells that are a 1 round action are the ones that take effect just before your next turn, but they can also be disrupted up until then. A spontaneous caster using meta magic is casting as a full round action, not a 1 round action. So it doesn’t get you any extra duration (other than what extend would normally give you).

A full round cast and a 1 round cast are two different things. Spells that are a full round action still take effect on the round they are cast. Spells that are a 1 round action are the ones that take effect just before your next turn, but they can also be disrupted up until then. A spontaneous caster using meta magic is casting as a full round action, not a 1 round action. So it doesn’t get you any extra duration (other than what extend would normally give you).

Thank you for this information. It isn't present in my rulebook, but I found it in the wiki.

The closet I think you’re going to come is that you can start a full round action when you only have a standard. It then finishes on your next turn. However, it takes your standard action from your next turn as well (2 standard actions total), which effectively defeats what you are trying to do, since you wouldn’t be able to attack the round it finishes. I’m not seeing anything other than quickening the spell that would let you use it on the round that it is cast.

The closet I think you’re going to come is that you can start a full round action when you only have a standard. It then finishes on your next turn. However, it takes your standard action from your next turn as well (2 standard actions total), which effectively defeats what you are trying to do, since you wouldn’t be able to attack the round it finishes. I’m not seeing anything other than quickening the spell that would let you use it on the round that it is cast.

Ok, one last dumb question. It says "once per round, you can make a melee touch attack against a target within 15 feet". I assume, this can be an Attack of Opportunity as well? So, what is the threat range of the Lash? Is it 15 feet? 5 feet? Or it doesn't have a threat range at all and I need to hold a weapon in another hand to threaten anything and make AoOs?

Ferious Thune wrote:

The closet I think you’re going to come is that you can start a full round action when you only have a standard. It then finishes on your next turn. However, it takes your standard action from your next turn as well (2 standard actions total), which effectively defeats what you are trying to do, since you wouldn’t be able to attack the round it finishes. I’m not seeing anything other than quickening the spell that would let you use it on the round that it is cast.

Ok, one last dumb question. It says "once per round, you can make a melee touch attack against a target within 15 feet". I assume, this can be an Attack of Opportunity as well? So, what is the threat range of the Lash? Is it 15 feet? 5 feet? Or it doesn't have a threat range at all and I need to hold a weapon in another hand to threaten anything and make AoOs?

No, it works only with a Standard action and it doesn't threaten.

It is easy to miss it as it is explained how it works in two different places, but the Core Rulebook has the rule about spontaneous spellcasters, metamagic and one round action vs full-round actions.

Because the sorcerer or bard has not prepared the spell in a metamagic form in advance, he must apply the metamagic feat on the spot. Therefore, such a character must also take more time to cast a metamagic spell (one enhanced by a metamagic feat) than he does to cast a regular spell. If the spell’s normal casting time is a standard action, casting a metamagic version is a fullround action for a sorcerer or bard. (This isn’t the same as a 1-round casting time.)

Casting a Metamagic Spell: Sorcerers and bards must take more time to cast a metamagic spell (one enhanced by a metamagic feat) than a regular spell. If a spell’s normal casting time is 1 standard action, casting a metamagic version of the spell is a full-round action for a sorcerer or bard (except for spells modified by the Quicken Spell feat, which take 1 swift action to cast). Note that this isn’t the same as a spell with a 1-round casting time. Spells that take a full-round action to cast take effect in the same round that you begin casting, and you are not required to continue the invocations, gestures, and concentration until your next turn. For spells with a longer casting time, it takes an extra full-round action to cast the metamagic spell.

My playing group did spend about a year to really get how it works when we started playing 3rd ed. D&D.