I tested Warden in my own game and failed to reproduce any of the issues you reported. The point is that as soon as you use the orb, Warden kills thralls and approaches you immediately. He doesn't stand where he was waiting for you. Consequently, the exploit LZJ reported about gaining infinite xp by killing planar hounds without the warden interfering is not doable in my game. The invisible trap which triggers the second group of Yuan-Tis and Minonaturs near the warden will not triggerif you don't go near warden's original place (unless you practice cheesy running methods and try to run around the place instead of standing and fighting).

I have asked Raven to test it as well, but from what I see in my game, if a player doesn't play cheesily (i.e. doesn't run), he won't have to face any more creatures than Warden and his planar hounds. Warden will not summon those extra planar hounds if you do not run either.

I will send more updated info after more tests and after receiving Raven's report. Perhaps there is some possibilities which I have failed to notice. We shall see.

Cheers

UPDATE: Also, see my own report of the battle with Warden in its related thread.

Which is the correct name of the petrified boy? Tried every combination, but he always dies.

Is the number of amber golems at the crystal set fix to 4 or is it possible that there will be fewer? Im just curious , because in my final attempt were only 3

If you have not asked her brother's name when you met Amariel, you won't have the right option at the final stage of the quest. You should either reload to an old saved game before talking to Amariel or you have to continue the game without doing this quest. It's all intentional, of course.

Noble Efreeties are immune to Breach. They are not immune to spells of any certain level.