Special Rule about the Kind of Characters
As far as I'm concerned you can chose to play any kind of exalted you like: Solar, Lunar, Sidereal, Dragon-Blooded, Abyssal, Alchemical.
And if you prefer you can play any kind of other non-exalted you want: God-Blooded (any kind), Sorcerers (any kind), Dragon-Kings, Heroic Mortals and even Extras (only if you like challenge).
The only limitation is: have you read the book? You DON'T play a Sidereal if you never read the Sidereal core book!!!!
Once again it is up to the Game Master of the campaign you want to play to have the final word.
I'll talk for Servant of the Mist and the Anura campaign: as the campaign is special I don't accept Alchemical and Abyssals (except if they are not under the command of a Deathlord), and for other reasons I don't accept Demon-Blooded except if they have no contact whatsoever with their demonic creators.
Because the campaign is exalted-oriented, I give 3 dots in Inheritance (see p61 of the Players Guide) background to the God-Blooded. And the Thaumaturges have 3 dots in the Experience background (see p117 of the Players Guide), they can take up to 4 dots in the Knowledge background (see p118 of the Players Guide).
Maintenant pour les joueurs de la vallée des rêves, étant donné la possible difficulté des aventures et la demande importante de Quintessence qui sera requise pour certains passages importants, je suggère aux joueurs de jouer des Exaltés, mais s'ils veulent jouer autre chose je leur conseille dans ce cas de prendre les avantages: Essence Awareness et Essence Mastery (p120 et 121 du Players Guide). Les God-Blooded gagnent le Background Inheritance au niveau 4 (voir paragraphe ci-dessus) et les Thaumaturges Experience au niveau 4 eux aussi (et la possibilité de prendre Knowledge jusqu'au niveau 5).
Last things for the Merits and Flaws. I remind you the max for an Exalted is 10 points of FLAWS! I can accept non-officials Merits or Flaws but I want to know where you found them before.
PS: all the pages given are for the English versions of the books.