Tactical advice for Tarnor in the Sewers Options

[sturmvogel]

Having struggled mightily with Mencar Pebblecrusher's party (none of Keldorn's 3 Dispel Magics dropped Sorcerous Amon's protections (thank ghod for Emotion!)) I'm a bit concerned about trying to deal with Tarnor's crowd, which has always been more of a struggle for me in the regular game since I've never been a very tactically elegant player.
I gather than my normal tactic of invisibly sneaking up and letting off a double cloudkill has been deprecated by Sikret and would like some advice for my 1.2 million XP party consisting of:

Me R/C
Keldorn
Jahiera
Yoshio
Xan F/M
Kelsey

[sturmvogel]

Thanks for the quick reply, Leonidas. I hadn't even considered your approach, probably because I haven't actually scouted out their tactics; I was toying with Yoshio luring them down the corridor into his traps, which I generally never use.
What do you do about traps if you don't have a thief in the party? I'd hate to waste spell slots on find traps, etc. and I'm less than enthusiastic about just sucking up the damage and bashing my way into the chest or whatever. I was toying with the idea of trading Yoshio for Valygar as Sikret's item upgrades make him much more worthwhile, IMO, but I'm just not sure how to survive without a thief of some sort.

I've never used Mazzy, but I really question my ability to complete the whole Shade Lord quest at my current level which I'd need to finish to release her. Hell, I'm not confident of my ability to finish De'Arnisse Keep at this level.

How long do you expect Xan's stoneskins to last if he's the main melee fighter? Should the rest of my guys stand back and snipe while this is going on? Or should they close for melee combat a few rounds after everything has started?
I always carry normal weapons. A lesson learned many, many moons ago.

I've pretty much done all of the quests except the Unseeing Eye (gotta learn how to deal with Beholders without the Shield of Cheese) that don't involve IA upgrades so I'm running out of things to do within my tactical competence. If I get this one figured out maybe I'll try the Horrid Rakhasa next. Him I've already had two unpleasant experiences with so I'll be needing advice again.