Sorcerer Spells Known Engine

[Burntmint]

Is there anything preventing this combination from working to allow a Sorcerer to swap his spells known?
Firstly the 5th level Sorcerer spell Dragonblood Spellpact, which allows creatures with the Dragonblood subtype to trade Known spells, and secondly the 2nd level Sorcerer spell Essence of the Dragon, which gives touched creature the Dragonblood subtype.

If this works, it gives Sorcerers and possibly Favored Souls the ability to swap spells with any class that has spells known as a feature, such as the Bard, Favored Soul, Sorcerer, Teflammar Shadowlord, Trapsmith with the only major limitation being gold, time and experience. While this may be straying into CO territory, as far as I can tell the is works RAW.

[Burntmint]

As a second question, Is there any summonable spontaneous caster missing from this list?
Lesser Planar Binding
Sylph, CL 7-10, Sorcerer

Planar Binding
Sylph, CL 11-13, Sorcerer

Arcanaloth, CL 9, Sorcerer

Couatl, CL 9, Sorcerer, Cleric, Air, Good, Law

Lillend, CL 6, Bard

Greater Planar Binding
Formian Queen, CL 17, Sorcerer

Klurichir, CL 10, Sorcerer

Shator, CL 8, Sorcerer

Lesser Spirit Binding
Dragonblooded Ghost CL 1-5, Trapsmith, 1-8, Bard/Favored Soul, CL 1-11 Sorcerer

Cheshire Cat, CL 3, Sorcerer

Spirit Binding
Dragonblooded Ghost CL 1-16, Bard, Favored Soul, CL 19 Sorcerer

Rakshasa CL 7, Sorcerer

Gloura, CL 7, Bard

Immoth, CL 12, Sorcerer without Fire spells

Greater Spirit Binding
Dragonblooded Ghost, CL 1-20 Bard, Favored Soul, Sorcerer

Ak'Chazar Rakshasa CL 12, Sorcerer

Greater Dragon Ally
Tome Dragon, CL 19-21, Sorcerer, Druid /(Cleric + Feast, Luck, Trickery / Community, Protection / Glory, Law, Sun, War / Charm, Commerce,Travel / Air, Animal, Earth), Knowledge, All Sorcerer Conjuration and Divination

Dread Linnorm, CL 18, Sorcerer

Steel Dragon, CL 14-16, Sorcerer, Wizard

Hex Dragon CL 13-15, Sorcerer, Knowledge, All Sorcerer Enchantment and Necromancy

Brass Dragon CL 11-13, Cleric, Sorcerer, Chaos, Knowledge

Bronze Dragon CL 11-13, Cleric Sorcerer, Animal, Law, Water

Copper Dragon CL 11-13, Cleric, Sorcerer, Chaos, Earth, Trickery

Shadow Dragon CL 11-13, Cleric, Sorcerer, Chaos, Evil, Trickery

Blue Dragon, CL 9-11, Cleric, Sorcerer, Air, Evil, Law

Deep Dragon CL 9-11, Cleric, Sorcerer, Earth, Evil, Trickery

Fang Dragon CL 9-11, Cleric, Sorcerer, Chaos, Death, Magic, Protection

Gold Dragon CL 9-11, Cleric, Sorcerer, Air, Good, Law, Luck, Protection

Red Dragon CL 9-11, Cleric, Sorcerer, Chaos, Evil, Fire

Silver Dragon CL 9-11, Cleric, Sorcerer, Air, Good, Law, Sun

Song Dragon CL 9-11, Cleric, Sorcerer, Healing, Travel, Trickery

[Anthrowhale]

Dragonblood Spell-pact is potentially quite powerful as you suggest. A party with multiple casters could effectively trade spells amongst themselves in interesting ways.

Polymorph is a more versatile approach to gaining the dragonblood subtype (or dragon type), which might matter on a sorcerer build.

Whether or not monsters have XP to expend for a spell is up to the DM.

[Burntmint]

Thanks, I've been going down the rabbit hole of total optimization on the Sorcerer, and it has a few interesting points that require working with the DM. For instance in the PHB the Sorcerers spells known has more open ended wording on the selection of spells for the Sorcerer than any other class, and Oriental Adventures states that the Sorcerer is allowed access to the Wu-Jen or Sor/Wiz list.