[mad=dog]

1) Personally I'd say you don't really need a tank. Perhaps for the first few levels, but otherwise no. One bet could be Hear'Dalis as point. He can buff himself with Mirror Image, Mislead, Stoneskin and that lot to compensate for low HP and still deal some fine damage with the right equipment. Later on he can do tricks with offensive spin and traps. I'd take Jan as the thief. You don't need that much thieving skills anyhow and Hear'Dalis will have the pickpocket side covered so you can invest Jans points elsewhere. Once Hear gets UAI he can lend Jans gear to boost his pickpocket skills on a need basis. Top up with your favorite wizards if you want to. Edwin (a natural pick), Imoen (if you can stand her yapping), Nalia (if you can stand her yapping), Aerie (for an extra C/M super killer).
My two cents. If you are more comfortable with something up front to suck damage please do so.

2) Yep. Furthermore your Cleric HLAs are counted as level 8 and can go into your contingencies and sequencers as such. Nasty nasty nasty.