MoonSong
Rules-lawyering drama queen but not a munchkin
Mechanically, I think WotC missed the boat by making metamagic the sorcerer's gig. I would have made them the con caster, made their noncantrip spell list the concentration spells from the wizard, bard, and warlock (subclasses could add concentration spells from the druid and cleric), and restrict the war mage feat to 11th level or higher characters. Metamagic could go to magic items (get your wand of twinning for 20 gps....). As high con types, they would make more con saves so it is less likely that their concentration spells will be disrupted--sorcerers are so in tune with magic it is hard to break their spells by hitting them like it is for other casters.....Plus sorcerers ought to have mutant (hybrid) vitality.
Thematically (and I admit this doesn't quite square with the mechanical idea), I like the thought that the sorcerer only thinks he/she is a human, elf, dwarf, etc., but is really a nascent elemental/dragon/demon/angel, etc. Kind of protective camouflage. As they level up, their "true selves" manifest more.
No offense, but this would be very off-putting. Changing form Cha to Con really changes the way the class plays and the concepts that can be played with them. (Only the sorcerer from the Radiance uses Con, curiously it is very close to your ideas) The "Actually a dragon/angel whatever in disguise" could be interesting, but robs the class of the every(wo)man aspect it has. Out of all the casters, the sorcerer is the only one that can truly come from anywhere without any mandatory action in the background -like selling your soul, deovting to a deity, devoting to nature, study music like crazy, study a lot of books- conceptually -though not so much in practicce with the rigid bloodlines we have so far- it is the most generic of them, flavor poisoning would be a disservice, not a plus IMO.
I would have wanted to see a sorcerer that was more of the wizard's equal, maybe with metamagic open to all via feats, but to be truly equivalent. Instead of "know way less than the wizard can prepare but compensate it with metamagic", I would prefer to "know more spells than the wizard can prepare, but they are set in stone". With the sorcerer knowing lets say five spells at first level, (for the wizard's 3-4 prepared), and scale so they end up with 30 at third level -against the wizard's 25) just with some class features to reinforce the flavor, like not needing VSM, except for costly spells, maybe a couple extra cantrips to off-set the lack of ritual caster and with all simple weapons (and the chance to get extra attack in order to focus spellcasting on non-combat).