Is there an obvious way to deal with Strength/Constitution damage? Those shadows are fucking scumbags.
Not really no, the shadows and the mummies are the hardest part of trying to handle it at a low level. You can try summons to keep them distracted, otherwise it comes down to a certain amount of luck.
The shadows were hard and I needed a couple of reloads to kill one of the two casters in the first round with a charge and an Energy Missile, but the mummies + vampire was a breeze.
With Greater Spell Focus, my Druid had an 85% chance of hitting with Quicksand and you can aim it so that it hits both a mummy and the vampire. I surrounded the other mummy with a Summon Crocodile and a Tentacled Horror, then I charged in with my two melee guys. The summoned creatures tanked the ability damage and were able to deal enough damage to take down both mummies with the help of 2 Scorching Ray and 2 Energy Missile. I wasted A LOT of resources (a domain power usage, 2 level 2 Druid Spells, 2 level 2 Wizard spells and 6 power points on the Psion), but I came out from the fight without a single damage or reload.
Up until now, the Aberration domain with maxed Charisma, Extra Turning, Augment Summoning and Summon Mastery was the strongest tool at my disposal. However, Quicksand is a gift from the gods. I just hope I can fucking rest now...
Ah, the dragon was a real pushover: he failed the save against Glitterdust and went down in three rounds without doing anything worthy of note. If there is no extra boss behind the door, this death snare thing is extremely easy at level 3 with a non-joke party. However, if now I have to face a boss without resting, Pierre is a monster.