No, only portraits of your class/gender, sorry.
Yes, three. They're all very strong, but I consider the Icy Elf the best because they have good melee skills. But they're all very good. Having two is fine, or even three, but I don't like elves. I only recommend taking one because not only are they really powerful, no, you can also get some fine "roleplaying" with them in some of the games. I don't know the differences by heart, but I remember that the wood/silvan elf is the hardest to roll and that's he's the best for ranged combat. (The best kind of combat, especially in RoA 2, and even more so in 3)
Opposing Specializations? When you make a normal Mage you get to select what spell-school he is focused on. This selection allows you to allocate 3 skill-raises to that school instead of the usual 2, if it's a mage spell, and 2 points instead of 1 if it's a non-mage spell in that school. Very useful to get, say, Transversalis early.
Schools that are good: Combat, Demonology, Movement, Altertation (not in that order). Just pick two and make sure one of the wizards works on Transversalis. I recommend two wizards because there's just SO many spells to work on, and while an experienced player can manage with one wizard, I recommend two for someone who is new to this game.
Thorwalians are completely useless. Well, not completely, but a dwarf is better in every conceivable way. Yes, Thorwalians get a nice skill spread. This is good in P&P. In RoA, however, you will hardly ever benefit from the skills they do have and are better off just taking a dwarf who has the added bonus of being good at haggling and lock-picking, two skills that are actually good. Dwarves do have a problem compared to Thorwalians: they can't swim well. You have to raise their swim skill until they're level 8 or so, two raises each level, so they won't drown pitifully in RoA 2 and 3.
The role? Well. Fighters fight well. Dwarves fight pretty much just as well as fighters, and Thorwalians fight pretty much just as well as fighters too. However, non-Fighters can use the very deadly poisons, becoming about three times more powerful. The drawback? They hit a little less often, but really, just a little. Maybe 10% or so. So think of it this way:
Fighter - can take damage well, hits hard and often
Dwarf - hits hard, high HP, can use poison, can open locks
Thorwalian - hits hard, can use poison, can learn some thief skills
Fighters take the role of the tank and damage dealer. Dwarves and Thorwalians are damage dealers (but also, tanks, since they get awesome armor) too, just a tiny bit less good who instead get some extras in their skill-spread, like their fleeting thief-skills. But it's really not that much and you'll see that both your fighter and your dwarf/thorwalian kick ass pretty hard.
And since they all three can wear the best armor, the "can take damage well" advantage of the fighter is a bit moot... But I still recommend having one, just to have another fellow in melee and to use the best weapons other classes can't use, like the Ox Herd.