Draconic Bloodline Arcana with Breath Weapon

Bloodline Arcana: Whenever you cast a spell with an energy descriptor that matches your draconic bloodline's energy type, that spell deals +1 point of damage per die rolled.

Breath Weapon (Su): At 9th level, you gain a breath weapon. This breath weapon deals 1d6 points of damage of your energy type per sorcerer level. Those caught in the area of the breath receive a Reflex save for half damage. The DC of this save is equal to 10 + 1/2 your sorcerer level + your Charisma modifier. The shape of the breath weapon depends on your dragon type (as indicated on the above chart). At 9th level, you can use this ability once per day. At 17th level, you can use this ability twice per day. At 20th level, you can use this ability three times per day.

Supernatural abilities are magical attacks, defenses, and qualities. These abilities can be always active or they can require a specific action to utilize. The supernatural ability's description includes information on how it is used and its effects.

main question does it work together?

1. 11 lvl draconic sorcerer, does she breath 11d6 or 11d6+11?

additional questions:
Robe of Arcane Heritage:
When a sorcerer dons a robe of arcane heritage, the stitching pulls itself apart and reweaves to match her particular sorcerer bloodline. The wearer treats her sorcerer level as 4 higher than normal for the purpose of determining what bloodline powers she can use and their effects.

2. with Robe of Arcane Heritage, does she breath 15d6 or 15d6 + 15?
2a. DC 17 +charisma mod?

3. also Robe only works only with one bloodline?(if crossbloded)

These elegant, dark purple robes are usually decorated with gold stitching suggesting a particular sorcerer bloodline, though some might indicate a family tree.

3a. If so does it mean, it must be Blue Draconic Robe of Heritage?

thank you!

1. The Breath Weapon is not a spell. The Arcana specifies a spell. 11d6, no +11.

2. Still 15D6.
2a. DC would be 17+Cha.

3. The Robe would affect all of a Sorcerer's bloodline powers, so crossblooding is fine.
3a. Strictly speaking the Robe doesn't distinguish between subtypes, though as that's nothing but flavor there's no reason why it couldn't if you so desired. Since the Robe reconstructs itself to match its bloodline, a (Blue) Draconic Robe of Arcane Heritage for you might be a Destined Robe of Arcane Heritage for Jimmy and a (Silver) Draconic Robe of Arcane Heritage for Timmy.

1) it quite clearly states 1d6 per level, so it would so 11d6 at 11th level. It doesn't say 1d6 per level plus your level, or (1d6+1) per level.

2) apparently, yes, it would increase your effective level by 4, so it would be 15d6 at level 11.

3) that one's a bit dicey, I don't know. Check to see if there is a FAQ regarding the cross blooded.

3a) I don't know what you mean by this.