I love the way that imaginations are running wild in this thread, but I think there are really two separate themes that the design team has to make some choices on:

• Story-telling / flavor
  • If we're using a Channeler's background to create a more colorful back-story, then I think the choice of personal history/background is more important than the choice of profession.
  • At the end of the day, "profession" is too often just a fantasy cliche these days and adds very little to the storytelling.
• Game mechanic
  
  • Lots of games allow you to choose profession or personal history to influence a Channeler's bonuses--this is a nice way to cater to a player's play style preferences, and adds more replayability.
  • If you go this way, I'm not sure that allowing 50 or 100 different profession choices does much for flavor.  It makes me feel more like I'm playing a spreadsheet, which was the only complaint I ever had with either of the GalCiv games.
    
  • If you want more powerful "skills" like in the old Master of Magic, I'd suggest doing that at the cost of other Channeler abilities--anything that's likely to get too powerful should be incorporated into the whole start-up mechanism.
  • I also like the idea of choices that don't just provide bonuses, but also introduce penalties or in-game limitations.  Those are the kind of choices you agonize over, and that's what drives in-game suspense for turn-based games.  The best games make you face tough choices, and those choices don't just revolve around "What's the opportunity cost of doing this first and that second?"

I don't personally mind building a "spread sheet" sov, if I get to have enough customization to make him distinctly unique. Wether that is by backstory (only useful in Role Play MP games) or some unique mechanic I get to add in that normally isn't available.

For instance, there is a "hidden" backstory, or something ... Hopefully Player created, were a certain combination of Talents and Weaknesses allows you to buy a Hidden Talent or Profession. In this way, you can create your own "extra" thing, which hopefully gives only slightly more than it takes away, for a certain style of play.

Now, the second option does seem a bit watery, so I would venture that such a thing would only be for mods.

One such unique trait could be ... recieves food from swamps (can build farms on swamps) but cannot move across desert/ half strength on desert.

Or, Cavalry troops train more quickly, and start with more HP at no additional cost, however all non cavalry troops take a hit in HP (about 10%).

Or, religious units (Fire) start with a bonus increased movement and attack speed (at no additional cost) and their fire-spells cost money rather than mana. In addition, any water spells (or spells that require water shards) cost money AND mana.