Playing on PC.  Just beat the 
 so I'm still fairly early.  So far, I only have Alistair as a full-blown party member. I'm playing the combat with tons of pausing, practically playing it like a turn-based SRPG.  I'm finding it extremely challenging, but fun.
Any tips on getting a good party going?  My main is a mage, and I plan on using Morrigan (I played it a bit on PS3 earlier so I know how she plays) as well to have 2 mages in tandem.  I was thinking of rounding it off with a tank character and an archer maybe?  Any recommendations for a good tank?  I know the dog is good, but I'd rather use a human character.  
Are archers good, or am I better off with two tanks? Is there a really good archer that isn't an elf (for some reason I dislike elf characters), preferably female?
How about a character that can use both bows and melee effectively?  
And what's the deal with Rogues?  Am I missing out on good loot if I can't open chests, or is it pretty much just crap to fill my inventory?
Sorry for the deluge of questions- I'm just really finding the combat tough and I want to try and maximize my potential in that regard.
Any opinions are appreciated.