Improved Familiar Questions

[Tyrantherus]

So one of my spellcasting characters are getting close to improved familiar, and want some verifications on some understandings about improved familiars.

When I get the improved familiar ability, my character is going to have 1 level in spellslinger and 6 levels in arcane bloodline sorcerer. As per wording of the arcane sorcerer, wizard levels contribute to the levels for the familiar.

So, when I would gain the faerie dragon familiar, for example...

The faerie dragon would have an HD of 7.

The number of hit points would be equal to half of my characters total hit points rounded down.

The faerie dragon's base attack bonus would be +3 due to sorcerer levels, and the familiar would use the dexterity modifier to calculate the familiar's melee attack bonus with natural weapons per wording on familiar basics here.
http://www.d20pfsrd.com/classes/core-classes/wizard/familiar

In another thread, a person mentioned that the HD often determines the level of which a caster determines the strength of their spells. If this is the case, would the Grease spell that the faerie dragon knows have a duration of 7 minutes instead of its normal 3 minutes as per original wording of the faerie dragon since it is originally treated as a 3rd-level sorcerer? In addition, does the HD of the faerie dragon effect its breath weapon in any way?

[Tiems]

The HD of your familiar never increase.
It gains more HP based on the owner's HP, but nowhere does it mention an increase in HD for familiars.

[Ashram]

What Tiems said. The familiar is TREATED as having HD equal to their normal HD or to their master's character level, whichever is higher, but their normal, base HD stays the same.

http://paizo.com/pathfinderRPG/prd/classes/wizard.html#_familiars

[Noir le Lotus]

Ashram wrote:

What Tiems said. The familiar is TREATED as having HD equal to their normal HD or to their master's sorcerer level, whichever is higher, but their normal, base HD stays the same.

http://paizo.com/pathfinderRPG/prd/classes/wizard.html#_familiars

Fixed !!

[Dekalinder]

Noir le Lotus wrote:

Fixed !!

No, bugged. The original was correct. Direct quote is

Core Rulebook wrote:

Hit Dice: For the purpose of effects related to number of Hit Dice, use the master's character level or the familiar's normal HD total, whichever is higher.

Levels in fighter for explample counts both toward the familiar hit dice and for his hit points calculation.