I'm at Level 14 with a warrior specialized in berserk and champion. I'm playing her as a good but pushy character. I get on Morrigan's nerves, but Alistair likes me just fine. I'm dumping most of my level-up points into strength and constitution, with some going into everything else except magic. I'm leaving all magic to Morrigan so far, though I'm now playing through a dream world in the Mage's tower. That mission put a healer in my party. I left the Rogue behind. Morrigan is just too important.
I wanted my first character to be a very straightforward tank, while I got through the game's learning curve. Since I can take over any party character at any time, I've been switching a lot to Morrigan, and see what she can do. I know the PC version of the game works somewhat differently. On the 360, I have a radial menu that pauses the action whenever I invoke it. By default, you're supposed to hold down a trigger to keep it open, but I changed that to a toggle. Then lets me choose an action from any character, then it goes back to real time, though I can immediately call up the menu again, and issue the next command for anyone. Party members all have a tactics list that is executed in order. (I imagine the PC version has this as well?) So you have Condition: Action X however many slots you have developed for each character. They start out with 5. I've been playing with this programming quite a bit as well, so there are some decent default behaviors during battles. It's all a micromanager's delight.
I've been really impressed with the story so far. There is so much history behind the scenes. On the down side, I'm not terribly impressed with being taken out of the world and into an overworld map where you see your trail move from one location to another, with the occasional random battle or other encounter interrupting it. I'm too spoiled by the Elder Scrolls world here.