Hello. Are elite characters worth it? I became a Warlock, and don't seem to have access to learn new fire spells. Is this true? Also, can you only have one of each elite type of character in your group? Finally, where is the training area for the thief?

TIA
Blacksword the Doomgiver

Theres an old saying "If you can't find the thieves guild, your not good enough to join it!"

Seriously though, Thieves train at the pawnshop, but there is no pawnshop in the first city, you have to wait till you get to is'd na.

Yes, elite characters are definitely worth it.
About your warlock: you can't learn higher level spells than your current role level, so until your warlock is level 4 he can't learn new level 4 spells (although he can cast those he already knows). Naturally he still needs his fire skill to be at least level 4 too.
Note that in this the warlock is an exception in that he can still normally advance in spell books of his former role(s). Other roles can only learn spells of former roles at half their skill, so p.e. if you switch from priest (spirit and vine) to monk (spirit only) you need to be level 8 in the vine skill to be able to learn 4th level spells. This is something to think about before changing roles: I changed my priest too soon, and I have never obtained to 'cure' spell (vine 6), the only spell to cure diseases.

You can become elite roles with any character you want, as long as they pay the money and complete the quest. You can also switch from one elite role to another, but never to a basic role, nor to a role you already have been. (In contrast you can only become a special role (assassin etc.) with 1 character. But that's only for much later.)

Except if you take the Assassin's dagger and shift it into someone else's inventory while the Pawn-Broker is still chewin through the "You want to be an Assassin" speech. Also lets you keep the assassins dagger, which is still my best weapon above Sword of Argus and Mavin.