Ok, just some recommendations. First of all, splitting the enemies up is a must, and some grappling summons are a great idea. You mentioned that there might be some teleport restrictions of the room. These will apply to your enemies too. One thing that might be helpful for everyone here would be an approximate size of the room.
First round, have the cleric cast a quickened heal on the paladin, and lay out that firestorm, target the queen and king, and or course whatever else you can fit in.
Have the diviner target the queen and king with his most powerful attack spell.
Have the sorcerer lay down a wall of force to seal off the gith mooks, and if possible the slaadi too. Throw out the bluff comment, and summon a giant constrictor, have it grapple with the queen. This should slow her down quite a bit.
Have the paladin charge in. Hopefully the death ward will keep him whole. Simply put, he look like a beast in melee. Smite the queen and then next round just tear into her will all the smiting wrath you have. As a high level psionicist, she is the most dangerous and must die first. Your tiger can help you or keep whatever mooks aren't trapped busy.
The other characters should engage the queen also, and if not possible, then the king. If it is ok for the cleric to do so, summon that red slaadi to sow doubt and add another grappler for the queen. I wouldn't be surprised that the archer can't get through the walls. If you can get a fly on him, he may have enough mobility to still get in his attacks.
Next round, just keep pounding, keep up the pressure, get as many spells into play per round as possible. An alienist summon of a few combat machines (celestial dire lions would be brutal). Heals on the queen are a must when the ranged spells get exhausted. Once the king and queen are dead (and hopefully the area effects killed a lot of the mooks) clean up the leftovers.
I don't think a good DM would give you guys anything absolutely overwhelming without a clue as to how to evade the situation. Retreat sounds risky. Based on the opening read, the glyphs reset (the paladin was thrown back into one he had already set off, and it went off again), and if they're being pursued, they won't have time to heal during the escape.
Good luck, I hope that helps.